https://en.bitcoin.it/w/api.php?action=feedcontributions&user=Furunodo&feedformat=atomBitcoin Wiki - User contributions [en]2024-03-28T21:12:08ZUser contributionsMediaWiki 1.30.0https://en.bitcoin.it/w/index.php?title=Category:Block_chain_browsers&diff=68165Category:Block chain browsers2020-08-22T15:12:31Z<p>Furunodo: If you do need to use a 3rd party block explorer, do it through a Tor onion service. For example Blockstream's explorer is reachable at http://explorerzydxu5ecjrkwceayqybizmpjjznk5izmitf2modhcusuqlid.onion/ - or less ideal, through a VPN.</p>
<hr />
<div>A Bitcoin [[block chain browser]] is an application, typically web-based, that allow users to search and navigate the Bitcoin [[block chain]].<br />
<br />
Note that using block chain browsers to check addresses under your control or to which you have sent money can be problematic for your [[privacy]].<br />
<br />
It can be a good idea to get software such as [https://github.com/janoside/btc-rpc-explorer BTC RPC Explorer] and run that on hardware that you control yourself, and connect it to your own [[full node]].<br />
<br />
If you do need to use a 3rd party block explorer, do it through a [[Tor]] onion service. For example [[Blockstream]]'s explorer is reachable at http://explorerzydxu5ecjrkwceayqybizmpjjznk5izmitf2modhcusuqlid.onion/ - or less ideal, through a VPN.<br />
<br />
== List of online Bitcoin block chain browsers ==<br />
<br />
=== 2020 ===<br />
* https://bitinfocharts.com/bitcoin/explorer/<br />
* blockchains.io/<br />
* blockonomics.co/<br />
* blockseer.com/<br />
* btc.bitaps.com/<br />
* chain.localbitcoins.com/<br />
* chain.so/<br />
* chainflyer.bitflyer.jp<br />
* https://bitaps.com/<br />
* https://blockpath.com/<br />
* https://blockstream.info/<br />
* https://btc.com/<br />
* https://chaindex.com/blockchain/<br />
* https://explorer.btc21.org/<br />
* https://learnmeabitcoin.com/explorer/node/<br />
* https://live.blockcypher.com/<br />
* https://oxt.me/<br />
* https://sochain.com/btc<br />
* https://www.kycp.org/<br />
* https://www.localbitcoinschain.com/<br />
* https://www.oklink.com/<br />
* https://www.smartbit.com.au/<br />
* https://yogh.io/<br />
* insight.bitpay.com<br />
* live.blockcypher.com/btc/<br />
* scorechain.com/<br />
* tradeblock.com/blockchain<br />
* http://blockchainsql.io/<br />
<br />
Local app:<br />
* orange - local electron app<br />
<br />
=== Older list ===<br />
* [https://apirone.com/btc/ Bitcoin Block Explorer with SegWit support]<br />
* [https://btc.bitaps.com Bitcoin Block Explorer]<br />
* [https://bitinfocharts.com/bitcoin/explorer/ BitInfoCharts]<br />
* [https://blockexplorer.com/ Bitcoin Block Explorer]<br />
* [https://bitcoinchain.com/block_explorer/ BitcoinChain]<br />
* [https://bitupper.com/en/explorer/bitcoin Bitupper Explorer]<br />
* [https://btc.blockchainhub.co.jp BlockhainHub]<br />
* [https://www.biteasy.com/blockchain/blocks bitEasy]<br />
* [https://blockchain.info/ Blockchain.info]<br />
* [https://live.blockcypher.com/ BlockCypher]<br />
* [https://www.blockonomics.co/ Blockonomics]<br />
* [https://blockpath.com/ Blockpath]<br />
* [https://btc.blockr.io/ blockr]<br />
* [https://www.blocktrail.com/BTC BlockTrail]<br />
* [https://chain.btc.com/ BTC Chain]<br />
* [http://chainflyer.bitflyer.jp/ chainFlyer]<br />
* [http://coinbelly.io/ Coinbelly]<br />
* [https://explorer.coinpayments.net/ CoinPayments]<br />
* [https://www.coinprism.info/ Coinprism]<br />
* [http://learnmeabitcoin.com/explorer/ learnmeabitcoin]<br />
* [https://chain.localbitcoins.com/ LocalBitcoins]<br />
* [https://smartbit.com.au Smartbit]<br />
* [https://chain.so/btc SoChain]<br />
* [https://tradeblock.com/blockchain/ TradeBlock]<br />
* [https://www.walletexplorer.com/ WalletExplorer]<br />
* [http://webbtc.com/ webBTC]<br />
* [https://chaindex.com/blockchain/ chaindex]<br />
* [https://BTC.com BTC.com]<br />
<br />
== List of online block chain browsers (testnet3) ==<br />
* [https://tbtc.bitaps.com/ Testnet explorer]<br />
* [https://tbtc.blockr.io/ blockr]<br />
* [https://tchain.btc.com/ BTC Chain]<br />
* [https://sandbox.smartbit.com.au/ Smartbit]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Category:Block_chain_browsers&diff=68164Category:Block chain browsers2020-08-22T15:09:25Z<p>Furunodo: Note that using block chain browsers to check addresses under your control or to which you have sent money can be problematic for your privacy. It can be a good idea to get software such as [https://github.com/janoside/btc-rpc-explorer BTC RPC Explor</p>
<hr />
<div>A Bitcoin [[block chain browser]] is an application, typically web-based, that allow users to search and navigate the Bitcoin [[block chain]].<br />
<br />
Note that using block chain browsers to check addresses under your control or to which you have sent money can be problematic for your [[privacy]].<br />
<br />
It can be a good idea to get software such as [https://github.com/janoside/btc-rpc-explorer BTC RPC Explorer] and run that on hardware that you control yourself, and connect it to your own [[full node]].<br />
<br />
== List of online Bitcoin block chain browsers ==<br />
<br />
=== 2020 ===<br />
* https://bitinfocharts.com/bitcoin/explorer/<br />
* blockchains.io/<br />
* blockonomics.co/<br />
* blockseer.com/<br />
* btc.bitaps.com/<br />
* chain.localbitcoins.com/<br />
* chain.so/<br />
* chainflyer.bitflyer.jp<br />
* https://bitaps.com/<br />
* https://blockpath.com/<br />
* https://blockstream.info/<br />
* https://btc.com/<br />
* https://chaindex.com/blockchain/<br />
* https://explorer.btc21.org/<br />
* https://learnmeabitcoin.com/explorer/node/<br />
* https://live.blockcypher.com/<br />
* https://oxt.me/<br />
* https://sochain.com/btc<br />
* https://www.kycp.org/<br />
* https://www.localbitcoinschain.com/<br />
* https://www.oklink.com/<br />
* https://www.smartbit.com.au/<br />
* https://yogh.io/<br />
* insight.bitpay.com<br />
* live.blockcypher.com/btc/<br />
* scorechain.com/<br />
* tradeblock.com/blockchain<br />
* http://blockchainsql.io/<br />
<br />
Local app:<br />
* orange - local electron app<br />
<br />
=== Older list ===<br />
* [https://apirone.com/btc/ Bitcoin Block Explorer with SegWit support]<br />
* [https://btc.bitaps.com Bitcoin Block Explorer]<br />
* [https://bitinfocharts.com/bitcoin/explorer/ BitInfoCharts]<br />
* [https://blockexplorer.com/ Bitcoin Block Explorer]<br />
* [https://bitcoinchain.com/block_explorer/ BitcoinChain]<br />
* [https://bitupper.com/en/explorer/bitcoin Bitupper Explorer]<br />
* [https://btc.blockchainhub.co.jp BlockhainHub]<br />
* [https://www.biteasy.com/blockchain/blocks bitEasy]<br />
* [https://blockchain.info/ Blockchain.info]<br />
* [https://live.blockcypher.com/ BlockCypher]<br />
* [https://www.blockonomics.co/ Blockonomics]<br />
* [https://blockpath.com/ Blockpath]<br />
* [https://btc.blockr.io/ blockr]<br />
* [https://www.blocktrail.com/BTC BlockTrail]<br />
* [https://chain.btc.com/ BTC Chain]<br />
* [http://chainflyer.bitflyer.jp/ chainFlyer]<br />
* [http://coinbelly.io/ Coinbelly]<br />
* [https://explorer.coinpayments.net/ CoinPayments]<br />
* [https://www.coinprism.info/ Coinprism]<br />
* [http://learnmeabitcoin.com/explorer/ learnmeabitcoin]<br />
* [https://chain.localbitcoins.com/ LocalBitcoins]<br />
* [https://smartbit.com.au Smartbit]<br />
* [https://chain.so/btc SoChain]<br />
* [https://tradeblock.com/blockchain/ TradeBlock]<br />
* [https://www.walletexplorer.com/ WalletExplorer]<br />
* [http://webbtc.com/ webBTC]<br />
* [https://chaindex.com/blockchain/ chaindex]<br />
* [https://BTC.com BTC.com]<br />
<br />
== List of online block chain browsers (testnet3) ==<br />
* [https://tbtc.bitaps.com/ Testnet explorer]<br />
* [https://tbtc.blockr.io/ blockr]<br />
* [https://tchain.btc.com/ BTC Chain]<br />
* [https://sandbox.smartbit.com.au/ Smartbit]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Category_talk:Block_chain_browsers&diff=68163Category talk:Block chain browsers2020-08-22T15:04:49Z<p>Furunodo: :Cool. I put these on the page itself. Wanna help edit that? If a site is down or dysfunctional, just remove it. I'm also curious about orange, do you have a link for that? ~~~~</p>
<hr />
<div>about 50% of these are dead<br />
<br />
here's some that works<br />
<br />
bitinfocharts.com/bitcoin/explorer/<br />
blockchains.io/<br />
blockonomics.co/<br />
blockseer.com/<br />
btc.bitaps.com/<br />
chain.localbitcoins.com/<br />
chain.so/<br />
chainflyer.bitflyer.jp<br />
https://bitaps.com/<br />
https://blockpath.com/<br />
https://blockstream.info/<br />
https://btc.com/<br />
https://chaindex.com/blockchain/<br />
https://explorer.btc21.org/<br />
https://learnmeabitcoin.com/explorer/node/<br />
https://live.blockcypher.com/<br />
https://oxt.me/<br />
https://sochain.com/btc<br />
https://www.kycp.org/<br />
https://www.localbitcoinschain.com/<br />
https://www.oklink.com/<br />
https://www.smartbit.com.au/<br />
https://yogh.io/<br />
insight.bitpay.com<br />
live.blockcypher.com/btc/<br />
scorechain.com/<br />
tradeblock.com/blockchain<br />
orange - local electron app<br />
http://blockchainsql.io/<br />
<br />
:Cool. I put these on the page itself. Wanna help edit that? If a site is down or dysfunctional, just remove it. I'm also curious about orange, do you have a link for that? [[User:Furunodo|Furunodo]] ([[User talk:Furunodo|talk]]) 15:04, 22 August 2020 (UTC)</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Category:Block_chain_browsers&diff=68162Category:Block chain browsers2020-08-22T15:03:59Z<p>Furunodo: </p>
<hr />
<div>A Bitcoin [[block chain browser]] is an application, typically web-based, that allow users to search and navigate the Bitcoin [[block chain]].<br />
<br />
== List of online Bitcoin block chain browsers ==<br />
<br />
=== 2020 ===<br />
* https://bitinfocharts.com/bitcoin/explorer/<br />
* blockchains.io/<br />
* blockonomics.co/<br />
* blockseer.com/<br />
* btc.bitaps.com/<br />
* chain.localbitcoins.com/<br />
* chain.so/<br />
* chainflyer.bitflyer.jp<br />
* https://bitaps.com/<br />
* https://blockpath.com/<br />
* https://blockstream.info/<br />
* https://btc.com/<br />
* https://chaindex.com/blockchain/<br />
* https://explorer.btc21.org/<br />
* https://learnmeabitcoin.com/explorer/node/<br />
* https://live.blockcypher.com/<br />
* https://oxt.me/<br />
* https://sochain.com/btc<br />
* https://www.kycp.org/<br />
* https://www.localbitcoinschain.com/<br />
* https://www.oklink.com/<br />
* https://www.smartbit.com.au/<br />
* https://yogh.io/<br />
* insight.bitpay.com<br />
* live.blockcypher.com/btc/<br />
* scorechain.com/<br />
* tradeblock.com/blockchain<br />
* http://blockchainsql.io/<br />
<br />
Local app:<br />
* orange - local electron app<br />
<br />
=== Older list ===<br />
* [https://apirone.com/btc/ Bitcoin Block Explorer with SegWit support]<br />
* [https://btc.bitaps.com Bitcoin Block Explorer]<br />
* [https://bitinfocharts.com/bitcoin/explorer/ BitInfoCharts]<br />
* [https://blockexplorer.com/ Bitcoin Block Explorer]<br />
* [https://bitcoinchain.com/block_explorer/ BitcoinChain]<br />
* [https://bitupper.com/en/explorer/bitcoin Bitupper Explorer]<br />
* [https://btc.blockchainhub.co.jp BlockhainHub]<br />
* [https://www.biteasy.com/blockchain/blocks bitEasy]<br />
* [https://blockchain.info/ Blockchain.info]<br />
* [https://live.blockcypher.com/ BlockCypher]<br />
* [https://www.blockonomics.co/ Blockonomics]<br />
* [https://blockpath.com/ Blockpath]<br />
* [https://btc.blockr.io/ blockr]<br />
* [https://www.blocktrail.com/BTC BlockTrail]<br />
* [https://chain.btc.com/ BTC Chain]<br />
* [http://chainflyer.bitflyer.jp/ chainFlyer]<br />
* [http://coinbelly.io/ Coinbelly]<br />
* [https://explorer.coinpayments.net/ CoinPayments]<br />
* [https://www.coinprism.info/ Coinprism]<br />
* [http://learnmeabitcoin.com/explorer/ learnmeabitcoin]<br />
* [https://chain.localbitcoins.com/ LocalBitcoins]<br />
* [https://smartbit.com.au Smartbit]<br />
* [https://chain.so/btc SoChain]<br />
* [https://tradeblock.com/blockchain/ TradeBlock]<br />
* [https://www.walletexplorer.com/ WalletExplorer]<br />
* [http://webbtc.com/ webBTC]<br />
* [https://chaindex.com/blockchain/ chaindex]<br />
* [https://BTC.com BTC.com]<br />
<br />
== List of online block chain browsers (testnet3) ==<br />
* [https://tbtc.bitaps.com/ Testnet explorer]<br />
* [https://tbtc.blockr.io/ blockr]<br />
* [https://tchain.btc.com/ BTC Chain]<br />
* [https://sandbox.smartbit.com.au/ Smartbit]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Altcoin&diff=68098Altcoin2020-07-28T14:35:39Z<p>Furunodo: </p>
<hr />
<div>{{seealso|List of alternative cryptocurrencies}}<br />
'''Altcoins''' are cryptocurrencies other than [[Bitcoin]].<br />
<br />
The majority of altcoins are forks of Bitcoin with small uninteresting changes. This page categorises different ways altcoins have modified Bitcoin.<br />
<br />
Many people prefer the term "shitcoin" to clearly distinguish all these altcoins from Bitcoin. This term has even been used in US Congress in 2019.<br />
<br />
The two main innovations in Bitcoin are its digital scarcity and its censorship resistance. For every altcoin you can point out that 1. it's trying to copy Bitcoin and that 2. there's a clear person or group of people in charge. Thus it's very easy for someone else to copy an altcoin and try to push it with even more marketing efforts than the "original" altcoin. Additionally it's relatively easy for government actors to interfere with the workings of an altcoin (such as Ethereum) by simply knocking on the doors of whoever is behind the altcoin.<br />
<br />
Some people are able to make money when trading altcoins, but for most people it's much preferred to simply buy and hold bitcoin for the long run. A lot of people would have been much better off with this simple strategy. Many people think that they make money, but if you look at their total net worth in Bitcoin terms they lost both money and time by trading on so called shitcoin casinos.<br />
<br />
<br />
<br />
==Different proof-of-work algorithm==<br />
<br />
The PoW algorithm used for mining Bitcoin is SHA2.<br />
It was chosen because it is fast to verify and has been critically analyzed.<br />
SHA2 has had ASICs developed for it meaning there is a much smaller risk of centralization.<br />
The following mining algorithms are being used in different altcoins:<br />
<br />
*[[Scrypt proof of work]]<br />
*Combination of hashing algorithms in series (e.g. X11)<br />
*Combination of hashing algorithms in parallel (e.g. Myriad algorithm)<br />
<br />
The problem with having an algorithm that is "easy to mine with" (referring to the ability to CPU or GPU mine profitably) is that mining should be hard in order to secure the network. When a mining algorithm is difficult to make ASICs for, there is a higher barrier to entry. A high barrier to entry increases the time that the first group to create ASICs will monopolize the market (and the time the network is vulnerable to a 51% attack from a single source). Many argue that the creators or the developers could simply change the mining algorithm when an ASIC is developed, but this defeats the purpose of decentralized consensus by causing centralization.<ref>[https://download.wpsoftware.net/bitcoin/asic-faq.pdf ASIC FAQ]</ref><br />
<br />
If these cryptocurrencies do have a healthy number of companies producing ASICs and have avoided centralization, they still are using algorithms that take longer to verify than SHA2. Therefore, at best a cryptocurrencies with merely a hashing algorithm change are as good as an exact clone of Bitcoin and not better (however since Bitcoin already exists, an exact clone of Bitcoin has no innovation or value). If the hashing algorithm is slower, as most altcoin algorithms are, it is a disadvantage because it takes more processing time to validate a block and increases the number of organic re-orgs (makes it easier to double spend).<br />
<br />
==Proof Of Stake==<br />
<br />
In [[Proof of Stake]], instead of sacrificing energy to mine a block, a user must prove they own a certain amount of the cryptocurrency to generate a block. The more stake you own, the more likely you are to generate a block. In theory, this should prevent users from creating forks because it will devalue their stake and it should save a lot of energy.<br />
<br />
Proof of Stake sounds like a good idea, but ironically, there is the "Nothing at Stake" problem. Because mining Bitcoin is costly, it is not smart to waste your energy on a fork that won't earn you any money, however with Proof of Stake, it is free to mine a fork.<br />
<br />
An example of a nothing at stake attack is an attacker buying lots of "old stake" from users inexpensively (inexpensive to users who no longer have stake in the currency). This can be made convenient by offering small payments to users for uploading their wallet.dat. Eventually after accumulating enough "old stake", the user can begin creating blocks and destroying as many or more coin days than the network was at that time. This block generation can be repeated until it catches up to and beats the current main-chain very cheaply.<br />
<br />
There are also "stake grinding" attacks which require a trivial amount of currency. In a stake<ref>[https://bitcointalk.org/index.php?topic=131901.0 Peercoin Security Analysis]</ref> grinding attack, the attacker has a small amount of stake and goes through the history of the blockchain and finds places where their stake wins a block. In order to consecutively win, they modify the next block header until some stake they own wins once again. This attack requires a bit of computation, but definitely isn't impractical.<br />
<br />
Because these attacks exists, including Peercoin<ref>[https://github.com/ppcoin/ppcoin/blob/master/src/checkpoints.cpp#L370 Peercoin Source | Centralized Checkpointing Public Key]</ref> and Blackcoin<ref>[https://github.com/rat4/blackcoin/blob/master/src/checkpoints.cpp#L361 Blackcoin Source | Centralized Checkpointing Public Key]</ref> proof of stake cryptocurrencies have "master" public keys that control the blockchain.<br />
<br />
This class of cryptocurrency is either insecure or centralized, however proof of stake (based on a PoW currency) is useful in some systems because gaining stake is costly, but it isn't workable for bootstrapping distributed consensus.<br />
<br />
==Application Built on Top of a Cryptocurrency==<br />
<br />
Bitcoin is a lot like HTTP. It is an application layer protocol and tools can be built on it (like websites can be built on HTTP). There is a class of cryptocurrencies that promise features like casino websites and exchanges and anonymity protocols to be built on top of them.<br />
<br />
When creating a new website, one doesn't make a new protocol unless it is necessary. For example, HTTPS is an encrypted version of HTTP, therefore it is useful and necessary. When creating an app such as "[https://bitcointalk.org/index.php?topic=467857.0 DarkSend]", one doesn't need to make a new protocol such as "Darkcoin". This is synonymous to making an HTTPS alternative (eg. HTTPSX) for your new encrypted chat website and not adding any new security or functionality to HTTPSX.<br />
<br />
Because Darkcoin is by far the most popular cryptocurrency of this class, the Darkcoin example will be covered in this section.<br />
<br />
The Darkcoin devs created a tool called DarkSend. DarkSend is an implementation of coinjoin (an anonymity feature originally implemented in Bitcoin<ref>[https://bitcointalk.org/index.php?topic=279249.0 Coinjoin Outline | BitcoinTalk]</ref>) which utilizes the Darkcoin network to organize the coinjoins. If DarkSend becomes open source and is useful, it will be ported to Bitcoin with a few small modifications. These changes won't be a hardfork, they will likely involve the masternodes being paid by those they are coinjoining for rather than the block reward, which is already possible and implemented for Bitcoin. <ref>[https://www.wpsoftware.net/coinjoin/ Rotating Coinjoiner]</ref>Currently one must hold 1000DRK to become a DarkSend masternodes. Masternodes are paid 10% of the block reward.<ref>[https://darkcointalk.org/threads/darkcoin-update-masternode-requirements-masternode-payments.225/ DarkSend Payment Scheme]</ref> This is a flawed reward scheme because while purchasing 1000DRK is trustlessly verifiable, a user running a DarkSend masternode isn't trustlessly verifiable. It is also costs bandwidth to run a masternode, therefore there is an incentive to buy 1000DRK and get a chance at the 10% block reward masternodes are being paid, but not actually act as a masternode. For this reason, DarkSend would work better if the masternodes were paid by those they were helping coinjoin, or if there wasn't a masternode at all and everyone collaborated in a decentralized fashion. The better implementation not vulnerable to tragedy of the commons is compatible with Bitcoin, therefore, the Darksend protocol serves no purpose.<br />
<br />
==Demographic Based Premined Cryptocurrencies==<br />
<br />
This is a new class of altcoin that is targeted at a certain demographic.<br />
<br />
All of these cryptocurrencies have a large premine intended to be paid to members of that demographic. Ultimately, all of these coins have suffered (or are suffering) their fate of an immediate sell off after the "[[airdrop]]" (term for distribution of coins to the target demographic) begins.<br />
<br />
Note: These cryptocurrencies aren't government initiatives, but are independently created for that demographic.<br />
<br />
==Useful Cryptocurrencies==<br />
<br />
A cryptocurrency is useful if it accomplishes a task that Bitcoin cannot.<br />
<br />
*Acting as a keystore for things like decentralized domain registration.<br />
*Having demmurage or some other economic system that is one of the [[prohibited changes]].<br />
*Allowing creation of and transmission of digital assets.<br />
<br />
==References==<br />
<references/></div>Furunodohttps://en.bitcoin.it/w/index.php?title=Altcoin&diff=68097Altcoin2020-07-28T13:31:53Z<p>Furunodo: Some people are able to make money when trading altcoins, but for most people it's much preferred to simply buy and hold bitcoin for the long run. A lot of people would have been much better off with this simple strategy. Many people think that they make</p>
<hr />
<div>{{seealso|List of alternative cryptocurrencies}}<br />
Altcoins are cryptocurrencies other than Bitcoin.<br />
<br />
The majority of altcoins are forks of Bitcoin with small uninteresting changes. This page categorises different ways altcoins have modified Bitcoin.<br />
<br />
Many people prefer the term "shitcoin" to clearly distinguish all these altcoins from Bitcoin. This term has even been used in US Congress in 2019.<br />
<br />
The two main innovations in Bitcoin are its digital scarcity and its censorship resistance. For every altcoin you can point out that 1. it's trying to copy Bitcoin and that 2. there's a clear person or group of people in charge. Thus it's very easy for someone else to copy an altcoin and try to push it with even more marketing efforts than the "original" altcoin. Additionally it's relatively easy for government actors to interfere with the workings of an altcoin (such as Ethereum) by simply knocking on the doors of whoever is behind the altcoin.<br />
<br />
Some people are able to make money when trading altcoins, but for most people it's much preferred to simply buy and hold bitcoin for the long run. A lot of people would have been much better off with this simple strategy. Many people think that they make money, but if you look at their total net worth in Bitcoin terms they lost both money and time by trading on so called shitcoin casinos.<br />
<br />
<br />
<br />
==Different proof-of-work algorithm==<br />
<br />
The PoW algorithm used for mining Bitcoin is SHA2.<br />
It was chosen because it is fast to verify and has been critically analyzed.<br />
SHA2 has had ASICs developed for it meaning there is a much smaller risk of centralization.<br />
The following mining algorithms are being used in different altcoins:<br />
<br />
*[[Scrypt proof of work]]<br />
*Combination of hashing algorithms in series (e.g. X11)<br />
*Combination of hashing algorithms in parallel (e.g. Myriad algorithm)<br />
<br />
The problem with having an algorithm that is "easy to mine with" (referring to the ability to CPU or GPU mine profitably) is that mining should be hard in order to secure the network. When a mining algorithm is difficult to make ASICs for, there is a higher barrier to entry. A high barrier to entry increases the time that the first group to create ASICs will monopolize the market (and the time the network is vulnerable to a 51% attack from a single source). Many argue that the creators or the developers could simply change the mining algorithm when an ASIC is developed, but this defeats the purpose of decentralized consensus by causing centralization.<ref>[https://download.wpsoftware.net/bitcoin/asic-faq.pdf ASIC FAQ]</ref><br />
<br />
If these cryptocurrencies do have a healthy number of companies producing ASICs and have avoided centralization, they still are using algorithms that take longer to verify than SHA2. Therefore, at best a cryptocurrencies with merely a hashing algorithm change are as good as an exact clone of Bitcoin and not better (however since Bitcoin already exists, an exact clone of Bitcoin has no innovation or value). If the hashing algorithm is slower, as most altcoin algorithms are, it is a disadvantage because it takes more processing time to validate a block and increases the number of organic re-orgs (makes it easier to double spend).<br />
<br />
==Proof Of Stake==<br />
<br />
In [[Proof of Stake]], instead of sacrificing energy to mine a block, a user must prove they own a certain amount of the cryptocurrency to generate a block. The more stake you own, the more likely you are to generate a block. In theory, this should prevent users from creating forks because it will devalue their stake and it should save a lot of energy.<br />
<br />
Proof of Stake sounds like a good idea, but ironically, there is the "Nothing at Stake" problem. Because mining Bitcoin is costly, it is not smart to waste your energy on a fork that won't earn you any money, however with Proof of Stake, it is free to mine a fork.<br />
<br />
An example of a nothing at stake attack is an attacker buying lots of "old stake" from users inexpensively (inexpensive to users who no longer have stake in the currency). This can be made convenient by offering small payments to users for uploading their wallet.dat. Eventually after accumulating enough "old stake", the user can begin creating blocks and destroying as many or more coin days than the network was at that time. This block generation can be repeated until it catches up to and beats the current main-chain very cheaply.<br />
<br />
There are also "stake grinding" attacks which require a trivial amount of currency. In a stake<ref>[https://bitcointalk.org/index.php?topic=131901.0 Peercoin Security Analysis]</ref> grinding attack, the attacker has a small amount of stake and goes through the history of the blockchain and finds places where their stake wins a block. In order to consecutively win, they modify the next block header until some stake they own wins once again. This attack requires a bit of computation, but definitely isn't impractical.<br />
<br />
Because these attacks exists, including Peercoin<ref>[https://github.com/ppcoin/ppcoin/blob/master/src/checkpoints.cpp#L370 Peercoin Source | Centralized Checkpointing Public Key]</ref> and Blackcoin<ref>[https://github.com/rat4/blackcoin/blob/master/src/checkpoints.cpp#L361 Blackcoin Source | Centralized Checkpointing Public Key]</ref> proof of stake cryptocurrencies have "master" public keys that control the blockchain.<br />
<br />
This class of cryptocurrency is either insecure or centralized, however proof of stake (based on a PoW currency) is useful in some systems because gaining stake is costly, but it isn't workable for bootstrapping distributed consensus.<br />
<br />
==Application Built on Top of a Cryptocurrency==<br />
<br />
Bitcoin is a lot like HTTP. It is an application layer protocol and tools can be built on it (like websites can be built on HTTP). There is a class of cryptocurrencies that promise features like casino websites and exchanges and anonymity protocols to be built on top of them.<br />
<br />
When creating a new website, one doesn't make a new protocol unless it is necessary. For example, HTTPS is an encrypted version of HTTP, therefore it is useful and necessary. When creating an app such as "[https://bitcointalk.org/index.php?topic=467857.0 DarkSend]", one doesn't need to make a new protocol such as "Darkcoin". This is synonymous to making an HTTPS alternative (eg. HTTPSX) for your new encrypted chat website and not adding any new security or functionality to HTTPSX.<br />
<br />
Because Darkcoin is by far the most popular cryptocurrency of this class, the Darkcoin example will be covered in this section.<br />
<br />
The Darkcoin devs created a tool called DarkSend. DarkSend is an implementation of coinjoin (an anonymity feature originally implemented in Bitcoin<ref>[https://bitcointalk.org/index.php?topic=279249.0 Coinjoin Outline | BitcoinTalk]</ref>) which utilizes the Darkcoin network to organize the coinjoins. If DarkSend becomes open source and is useful, it will be ported to Bitcoin with a few small modifications. These changes won't be a hardfork, they will likely involve the masternodes being paid by those they are coinjoining for rather than the block reward, which is already possible and implemented for Bitcoin. <ref>[https://www.wpsoftware.net/coinjoin/ Rotating Coinjoiner]</ref>Currently one must hold 1000DRK to become a DarkSend masternodes. Masternodes are paid 10% of the block reward.<ref>[https://darkcointalk.org/threads/darkcoin-update-masternode-requirements-masternode-payments.225/ DarkSend Payment Scheme]</ref> This is a flawed reward scheme because while purchasing 1000DRK is trustlessly verifiable, a user running a DarkSend masternode isn't trustlessly verifiable. It is also costs bandwidth to run a masternode, therefore there is an incentive to buy 1000DRK and get a chance at the 10% block reward masternodes are being paid, but not actually act as a masternode. For this reason, DarkSend would work better if the masternodes were paid by those they were helping coinjoin, or if there wasn't a masternode at all and everyone collaborated in a decentralized fashion. The better implementation not vulnerable to tragedy of the commons is compatible with Bitcoin, therefore, the Darksend protocol serves no purpose.<br />
<br />
==Demographic Based Premined Cryptocurrencies==<br />
<br />
This is a new class of altcoin that is targeted at a certain demographic.<br />
<br />
All of these cryptocurrencies have a large premine intended to be paid to members of that demographic. Ultimately, all of these coins have suffered (or are suffering) their fate of an immediate sell off after the "[[airdrop]]" (term for distribution of coins to the target demographic) begins.<br />
<br />
Note: These cryptocurrencies aren't government initiatives, but are independently created for that demographic.<br />
<br />
==Useful Cryptocurrencies==<br />
<br />
A cryptocurrency is useful if it accomplishes a task that Bitcoin cannot.<br />
<br />
*Acting as a keystore for things like decentralized domain registration.<br />
*Having demmurage or some other economic system that is one of the [[prohibited changes]].<br />
*Allowing creation of and transmission of digital assets.<br />
<br />
==References==<br />
<references/></div>Furunodohttps://en.bitcoin.it/w/index.php?title=Altcoin&diff=68096Altcoin2020-07-28T13:26:58Z<p>Furunodo: attempt at some clarification</p>
<hr />
<div>{{seealso|List of alternative cryptocurrencies}}<br />
Altcoins are cryptocurrencies other than Bitcoin.<br />
<br />
The majority of altcoins are forks of Bitcoin with small uninteresting changes. This page categorises different ways altcoins have modified Bitcoin.<br />
<br />
Many people prefer the term "shitcoin" to clearly distinguish all these altcoins from Bitcoin. This term has even been used in US Congress in 2019.<br />
<br />
The two main innovations in Bitcoin are its digital scarcity and its censorship resistance. For every altcoin you can point out that 1. it's trying to copy Bitcoin and that 2. there's a clear person or group of people in charge. Thus it's very easy for someone else to copy an altcoin and try to push it with even more marketing efforts than the "original" altcoin. Additionally it's relatively easy for government actors to interfere with the workings of an altcoin (such as Ethereum) by simply knocking on the doors of whoever is behind the altcoin.<br />
<br />
<br />
==Different proof-of-work algorithm==<br />
<br />
The PoW algorithm used for mining Bitcoin is SHA2.<br />
It was chosen because it is fast to verify and has been critically analyzed.<br />
SHA2 has had ASICs developed for it meaning there is a much smaller risk of centralization.<br />
The following mining algorithms are being used in different altcoins:<br />
<br />
*[[Scrypt proof of work]]<br />
*Combination of hashing algorithms in series (e.g. X11)<br />
*Combination of hashing algorithms in parallel (e.g. Myriad algorithm)<br />
<br />
The problem with having an algorithm that is "easy to mine with" (referring to the ability to CPU or GPU mine profitably) is that mining should be hard in order to secure the network. When a mining algorithm is difficult to make ASICs for, there is a higher barrier to entry. A high barrier to entry increases the time that the first group to create ASICs will monopolize the market (and the time the network is vulnerable to a 51% attack from a single source). Many argue that the creators or the developers could simply change the mining algorithm when an ASIC is developed, but this defeats the purpose of decentralized consensus by causing centralization.<ref>[https://download.wpsoftware.net/bitcoin/asic-faq.pdf ASIC FAQ]</ref><br />
<br />
If these cryptocurrencies do have a healthy number of companies producing ASICs and have avoided centralization, they still are using algorithms that take longer to verify than SHA2. Therefore, at best a cryptocurrencies with merely a hashing algorithm change are as good as an exact clone of Bitcoin and not better (however since Bitcoin already exists, an exact clone of Bitcoin has no innovation or value). If the hashing algorithm is slower, as most altcoin algorithms are, it is a disadvantage because it takes more processing time to validate a block and increases the number of organic re-orgs (makes it easier to double spend).<br />
<br />
==Proof Of Stake==<br />
<br />
In [[Proof of Stake]], instead of sacrificing energy to mine a block, a user must prove they own a certain amount of the cryptocurrency to generate a block. The more stake you own, the more likely you are to generate a block. In theory, this should prevent users from creating forks because it will devalue their stake and it should save a lot of energy.<br />
<br />
Proof of Stake sounds like a good idea, but ironically, there is the "Nothing at Stake" problem. Because mining Bitcoin is costly, it is not smart to waste your energy on a fork that won't earn you any money, however with Proof of Stake, it is free to mine a fork.<br />
<br />
An example of a nothing at stake attack is an attacker buying lots of "old stake" from users inexpensively (inexpensive to users who no longer have stake in the currency). This can be made convenient by offering small payments to users for uploading their wallet.dat. Eventually after accumulating enough "old stake", the user can begin creating blocks and destroying as many or more coin days than the network was at that time. This block generation can be repeated until it catches up to and beats the current main-chain very cheaply.<br />
<br />
There are also "stake grinding" attacks which require a trivial amount of currency. In a stake<ref>[https://bitcointalk.org/index.php?topic=131901.0 Peercoin Security Analysis]</ref> grinding attack, the attacker has a small amount of stake and goes through the history of the blockchain and finds places where their stake wins a block. In order to consecutively win, they modify the next block header until some stake they own wins once again. This attack requires a bit of computation, but definitely isn't impractical.<br />
<br />
Because these attacks exists, including Peercoin<ref>[https://github.com/ppcoin/ppcoin/blob/master/src/checkpoints.cpp#L370 Peercoin Source | Centralized Checkpointing Public Key]</ref> and Blackcoin<ref>[https://github.com/rat4/blackcoin/blob/master/src/checkpoints.cpp#L361 Blackcoin Source | Centralized Checkpointing Public Key]</ref> proof of stake cryptocurrencies have "master" public keys that control the blockchain.<br />
<br />
This class of cryptocurrency is either insecure or centralized, however proof of stake (based on a PoW currency) is useful in some systems because gaining stake is costly, but it isn't workable for bootstrapping distributed consensus.<br />
<br />
==Application Built on Top of a Cryptocurrency==<br />
<br />
Bitcoin is a lot like HTTP. It is an application layer protocol and tools can be built on it (like websites can be built on HTTP). There is a class of cryptocurrencies that promise features like casino websites and exchanges and anonymity protocols to be built on top of them.<br />
<br />
When creating a new website, one doesn't make a new protocol unless it is necessary. For example, HTTPS is an encrypted version of HTTP, therefore it is useful and necessary. When creating an app such as "[https://bitcointalk.org/index.php?topic=467857.0 DarkSend]", one doesn't need to make a new protocol such as "Darkcoin". This is synonymous to making an HTTPS alternative (eg. HTTPSX) for your new encrypted chat website and not adding any new security or functionality to HTTPSX.<br />
<br />
Because Darkcoin is by far the most popular cryptocurrency of this class, the Darkcoin example will be covered in this section.<br />
<br />
The Darkcoin devs created a tool called DarkSend. DarkSend is an implementation of coinjoin (an anonymity feature originally implemented in Bitcoin<ref>[https://bitcointalk.org/index.php?topic=279249.0 Coinjoin Outline | BitcoinTalk]</ref>) which utilizes the Darkcoin network to organize the coinjoins. If DarkSend becomes open source and is useful, it will be ported to Bitcoin with a few small modifications. These changes won't be a hardfork, they will likely involve the masternodes being paid by those they are coinjoining for rather than the block reward, which is already possible and implemented for Bitcoin. <ref>[https://www.wpsoftware.net/coinjoin/ Rotating Coinjoiner]</ref>Currently one must hold 1000DRK to become a DarkSend masternodes. Masternodes are paid 10% of the block reward.<ref>[https://darkcointalk.org/threads/darkcoin-update-masternode-requirements-masternode-payments.225/ DarkSend Payment Scheme]</ref> This is a flawed reward scheme because while purchasing 1000DRK is trustlessly verifiable, a user running a DarkSend masternode isn't trustlessly verifiable. It is also costs bandwidth to run a masternode, therefore there is an incentive to buy 1000DRK and get a chance at the 10% block reward masternodes are being paid, but not actually act as a masternode. For this reason, DarkSend would work better if the masternodes were paid by those they were helping coinjoin, or if there wasn't a masternode at all and everyone collaborated in a decentralized fashion. The better implementation not vulnerable to tragedy of the commons is compatible with Bitcoin, therefore, the Darksend protocol serves no purpose.<br />
<br />
==Demographic Based Premined Cryptocurrencies==<br />
<br />
This is a new class of altcoin that is targeted at a certain demographic.<br />
<br />
All of these cryptocurrencies have a large premine intended to be paid to members of that demographic. Ultimately, all of these coins have suffered (or are suffering) their fate of an immediate sell off after the "[[airdrop]]" (term for distribution of coins to the target demographic) begins.<br />
<br />
Note: These cryptocurrencies aren't government initiatives, but are independently created for that demographic.<br />
<br />
==Useful Cryptocurrencies==<br />
<br />
A cryptocurrency is useful if it accomplishes a task that Bitcoin cannot.<br />
<br />
*Acting as a keystore for things like decentralized domain registration.<br />
*Having demmurage or some other economic system that is one of the [[prohibited changes]].<br />
*Allowing creation of and transmission of digital assets.<br />
<br />
==References==<br />
<references/></div>Furunodohttps://en.bitcoin.it/w/index.php?title=Bitok.com&diff=68095Bitok.com2020-07-28T13:20:15Z<p>Furunodo: altcoins</p>
<hr />
<div>== BITOK.COM ==<br />
<br />
[http://www.bitok.com BITOK.COM] was a quick, trustworthy and user-friendly platform for trading [[altcoin]]s.<br />
== HISTORY ==<br />
<br />
Bitcoin Innovations LTD has launched the new cryptocurrency market exchange with broad variety of fiat money and cryptocoins in September, 2014.<br />
<br />
== INSTANT BITCOIN PURCHASE OPTION == <br />
<br />
[http://www.bitok.com BITOK.COM] supports an instant Bitcoin purchase opportunity to allow new users easily deposit and withdraw their funds, and begin trading immediately. <br />
<br />
Bitok.com offers wide range of payment providers, both for deposit and withdrawal. <br />
The main payment systems provided by Bitok are the following:<br />
* Visa/Mastercard (withdraw only)<br />
* PayPal (withdraw only)<br />
* Bitok vouchers<br />
* Wire Transfer<br />
* MoneyPolo<br />
* AstroPay<br />
* Perfect Money<br />
* OKPay<br />
* Alpha-Click<br />
* QIWI<br />
* Payeer<br />
* Advcash<br />
* BTC-E Code<br />
* and intermediary services.<br />
<br />
The detailed list of all Bitok payment partners could be found on [https://bitok.com/fees fees page].<br />
<br />
== TRADING PAIRS ==<br />
<br />
At Bitok.com, users are able to trade:<br />
<br />
* BTC/USD<br />
* BTC/EUR<br />
* BTC/RUB<br />
* LTC/USD<br />
* LTC/EUR<br />
* LTC/RUB<br />
* LTC/BTC<br />
* DOGE/USD<br />
* DOGE/EUR<br />
* DOGE/RUB<br />
* DOGE/BTC<br />
<br />
Bitok.com is continuously working on adding other fiat and cryptocurrencies, as well as most convenient payment processors.<br />
<br />
== TRADING ==<br />
<br />
Trading at Bitok.com allows you to actively trade your coins and get your profit on price differences. <br />
<br />
There is a number of features, such as trade history and dynamics, market volume and depth and the current exchange rates that makes managing investments simple and safe. <br />
The order list allows placing a limit order by setting a certain price for buying or selling Bitcoins.<br />
<br />
== MISSION ==<br />
<br />
As an officially registered company, Bitok.com takes serious precautions to ensure that customers’ personal information and funds remain as securely stored as possible. Trading is extremely fast at Bitok.com. <br />
<br />
== TEAM ==<br />
<br />
Behind Bitok.com there is a young and efficient team of technical professionals, who possess extensive knowledge and experience in IT projects of various direction and complexity. Developers of Bitok.com contribute all their skills and knowledge to the project and are constantly working on improving the services. They believe in what they do and are optimistic about the future of the cryptocurrencies. The goal is to become the most secure and trustworthy place for buying and selling cryptocurrency on the net. <br />
<br />
== SECURITY PLAN ==<br />
<br />
To exclude any fraud attempts, users of Bitok.com are recommended to enable the Two-Factor Authentication (2FA) on their accounts. Bitok.com suggests [http://en.wikipedia.org/wiki/Google_Authenticator Google Authenticator] 2FA application to its users. <br />
If needed, detailed logs of users’ actions are available to investigate any issues.<br />
<br />
== EXTERNAL LINKS ==<br />
<br />
*[http://www.bitok.com Bitok.com website ]<br />
*[https://www.facebook.com/official.bitok Bitok.com Facebook]<br />
*[https://twitter.com/Bitok_com Bitok.com Twitter ]<br />
<br />
<br />
[[Category:Defunct exchanges]]<br />
[[Category:Mining]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Mengmengbi&diff=68094Mengmengbi2020-07-28T13:19:46Z<p>Furunodo: altcoins</p>
<hr />
<div>== [[File:MMB.png|40px|link=https://www.mengmengbi.cn]] Mengmenbi (萌萌币) ==<br />
<br />
[https://www.mengmengbi.cn '''Mengmengbi (萌萌币)'''] is a trading platform for buying and selling Bitcoin in CNY currencies. Mengmengbi is powered by [https://www.anxpro.com '''ANX''']. The trading engine is built upon the LMAX Disruptor technology used by banks for their foreign currency exchange (FX) trading. The engine was designed to handle high volume, high throughput, and low latency trading.<br><br><br />
<br />
<br />
== Advantages ==<br />
<br />
• Powered by ANX<br><br />
• Zero Trading Fees<br><br />
• Instant processing of CNY deposits<br><br />
• Near realtime processing of CNY withdraways (Mon-Fri)<br><br />
• Gox compatible Trading API with BTC, [[altcoin]] support<br><br />
• Support Bitcoin and [[altcoin]]s<br />
• Zero bank transfer fees<br />
• Shared liquidity with ANX, one of the top 10 Bitcoin exchanges in the world<br><br />
• Multilingual support (English, Traditional Chinese, Simplified Chinese).<br><br />
<br />
== Security ==<br />
• Support Two-Factor Authentication greatly reducing online identity theft.<br><br />
• Mengmengbi is using an industry leading service provider for DDOS protection and our servers are hosted in a Tier 3+ ISO 27001/9001 compliant datacentre.<br><br />
• Mengmengbi supports two-factor authentication in addition to email verification for all crypto withdrawals.<br><br />
• Mengmengbi does not run a fractural reserve. All customer funds segregated and accounted for.<br><br><br />
<br />
<br />
[[Category:Defunct exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Cryptocomes&diff=68093Cryptocomes2020-07-28T13:19:09Z<p>Furunodo: altcoins</p>
<hr />
<div>{{infobox company|name=CryptoComes|image=[[File:Rsz_cryptocomes_logo_new.jpg]]<br />
|industry=News<br />
|founder=Cyril Gilson<br />
|foundation=February 1, 2018<br />
|website=https://www.cryptocomes.com/<br />
}}CryptoComes is a news, analysis and educational platform that covers the crypto industry, Blockchain and new gen tech.<br />
[https://cryptocomes.com/cyril-gilson Cyril Gilson] is Editor-in-Chief of CryptoComes. In 2015 - 2017 <ref>https://coinlive.io/interview/cyril</ref>, he worked as Editor-in-Chief of Cointelegraph.<br />
<br />
==CryptoComes Daily Pricewise==<br />
CryptoComes daily [https://cryptocomes.com/pricewise Pricewise] explains the latest price movements and tells you what to expect.<br />
<br />
==CryptoComes Coins Guide==<br />
CryptoComes [https://cryptocomes.com/guides/coins-guide Coins Guide] covers informative guides about [[altcoin]]s and how to deal with them.<br />
<br />
==References==<br />
<references/><br />
<br />
==External Links==<br />
* [https://cryptocomes.com/ CryptoComes Website]<br />
* [https://twitter.com/CryptoComes Twitter]<br />
* [https://www.facebook.com/CryptoComes/ Facebook]<br />
* [https://t.me/cryptocomes Telegram]<br />
* [https://www.youtube.com/cryptocomes Youtube]<br />
* [https://www.feedspot.com/infiniterss.php?q=site:https%3A%2F%2Fcryptocomes.com%2Frss_feed RSS Feed] <br />
* [https://news360.com/search/cryptocomes news360] <br />
* [https://www.linkedin.com/company/CryptoComes LinkedIn] <br />
* [https://www.trustpilot.com/review/cryptocomes.com TrustPilot] <br />
*[https://cryptocomes.com/priceindex/bitcoin-price-index Bitcoin Price Index]<br />
<br />
[[Category:Blogs]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=McxNOW&diff=68092McxNOW2020-07-28T13:17:38Z<p>Furunodo: </p>
<hr />
<div>'''McxNOW''' was a digital currency exchange allowing trading of bitcoin and altcoin digital currencies.<br />
<br />
The site will be going into a maintenance period beginning November 15 2014, which according to the site operator will take several weeks and destroy any coins that are not withdrawn by that date. Wallet data will also be deleted<ref>[https://mcxnow.com mcxNOW Exchange]</ref>.<br />
<br />
==Features==<br />
* Written entirely in C++ for speed and response.<ref>[https://mcxnow.com mcxNOW Exchange]</ref>.<br />
* No internet access to database for security.<br />
* 25% of all mcxNOW exchange fees go towards paying interest on deposits every 6 hours. No trading is required to earn interest payments<ref>[https://mcxnow.com/features.html mcxNOW Exchange Features and FAQ]</ref>.<br />
<br />
===Trading===<br />
<br />
====Fixed-point integer math trading engine====<br />
mcxNOW uses integers through the entire trade pipeline to ensure you aren't losing out and get precise results.<br />
<br />
====Anonymous Trading====<br />
No personal identification required.<br />
<br />
====Currency pairs====<br />
* BTC/[[LTC]]<br />
* BTC/MNV<br />
* BTC/[[DVC]]<br />
* BTC/WDC<br />
* BTC/CL<br />
* BTC/XPM<br />
* BTC/SC<br />
* BTC/PPC<br />
* BTC/FTC<br />
<br />
====Trading Fees====<br />
There is a 0.2% fee for each side of every trade, so 0.2% for the buyer (BTC fee) and 0.2% for the seller (altcoin fee).<br />
<br />
<br />
===Deposits===<br />
====Deposit Fees====<br />
There are no fees on bitcoin or alt-coin deposits.<br />
====Deposit Options====<br />
You may deposit any of the following:<br />
*Bitcoin<br />
*[[Litecoin]]<br />
*PrimeCoin<br />
*PeerCoin<br />
*Feathercoin<br />
*MinCoin<br />
*SolidCoin<br />
*[[Devcoin]]<br />
*WorldCoin<br />
*CopperLark<br />
<br />
===Withdraws===<br />
====Withdraw Options and Fees====<br />
*Bitcoin (Withdrawal Fee: 0.001BTC)<br />
*Litecoin (Withdrawal Fee: 0.02LTC)<br />
*PrimeCoin (Withdrawal Fee: 0.1MNC)<br />
*PeerCoin (Withdrawal Fee: 0.1PPC)<br />
*Feathercoin (Withdrawal Fee: 0.1FTC)<br />
*MinCoin (Withdrawal Fee: 0.1MNC)<br />
*SolidCoin (Withdrawal Fee: 0.4SC)<br />
*Devcoin (Withdrawal Fee: 50.0DVC)<br />
*WorldCoin (Withdrawal Fee: 0.4WDC)<br />
*CopperLark (Withdrawal Fee: 0.4CL)<br />
<br />
<br />
==References==<br />
<references /><br />
<br />
[[Category:Defunct exchanges]]<br />
[[Category:EWallets]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=HolyTransaction&diff=68091HolyTransaction2020-07-28T13:16:20Z<p>Furunodo: altcoins</p>
<hr />
<div>{{infobox company|name=HolyTransaction|image=[[Image:HolyTransaction_Logo.png|256px]]<br />
|trading_name=HolyTransaction<br />
|industry=[[Wallet]]<br />
|foundation=2014-02-16<br />
|location= Grand-Duchy of Luxembourg<br />
|parent= [http://holytransaction.com HolyTransaction SA]<br />
|pairs= BTC, [[altcoin]]s<br />
|website=https://holytransaction.com<br />
}}<br />
[https://www.holytransaction.com HolyTransaction] is your universal multi-currency wallet. It offers a simple and instant exchange among cryptocurrencies. It's designed for nontechnical users. Mobile wallet client is available on any device with HTML5 support.<br />
<br />
== Headquarter and Offices ==<br />
<br />
HolyTransaction is operated by HolyTransaction SA, which is a corporate entity registered in Luxembourg, with its headquarters in Luxembourg City.<br />
<br />
==Digital Currency Exchange==<br />
HolyTransaction is a multi-currency online wallet with simple and instant conversion between supported currencies - exchange between all popular currencies with a couple of clicks. Instantly send from one currency to another: you can send payments in one digital currency, and receive in another. <br />
<br />
==Send Bitcoin to anyone!==<br />
Send cryptocurrencies to a friend through Facebook, LinkedIn, Twitter, or email. You can send bitcoins to anyone, anywhere. If they don’t have a wallet, they will receive a notification with a link to redeem the funds.<br />
<br />
==Simple to use==<br />
With a simple, no-hassles gui. Anyone can use cryptocurrencies.<br />
<br />
==Cutting Edge Security==<br />
We follow the best industry practices and guarantee that your money is safe. We utilize both hot & cold storage.<br />
<br />
==API==<br />
Integrate cryptocurrency support into a website of any kind, from invoice processing to white-labeled multi-currency wallets.<br />
<br />
==History==<br />
<br />
* HolyTransaction Beta: February 16th 2014<br />
* HolyTransaction v1: April 30th 2014<br />
* HolyTransaction v1.5: July 14th 2014<br />
* HolyTransaction v2: October 2015<br />
* HolyTransaction v2.5: October 2016<br />
<br />
==External Links==<br />
<br />
* [https://www.holytransaction.com HolyTransaction] Official website<br />
* [https://bitcointalk.org/index.php?topic=472248.0 on BitcoinTalk] BitcoinTalk<br />
* [https://twitter.com/holytransaction HolyTransaction on Twitter]<br />
* [http://www.expresscoin.com/wallets/bitcoin/holytransaction How to Setup HolyTransaction Wallet] Quick guide to setup HolyTransaction<br />
<br />
==Screenshots==<br />
[[Image:Holytransaction_Screenshot_1.png|400px]]<br />
[[Image:Holytransaction_Screenshot_2.png|400px]]<br />
<br />
<br />
<br />
<br />
<br />
[[Category:EWallets]]<br />
[[Category:Wallets]]<br />
[[Category:Exchange]]<br />
[[Category:Services]]<br />
[[Category:Financial]]<br />
[[Category:Clients]]<br />
[[Category:Frontends]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Hardware_wallet&diff=68090Hardware wallet2020-07-28T13:14:26Z<p>Furunodo: /* BitBox02: Swiss made open source */ altcoins</p>
<hr />
<div>A '''hardware wallet''' is a special type of [[wallet|bitcoin wallet]] which stores the user's private keys in a secure hardware device.<br />
<br />
They have major advantages over standard software wallets:<br />
<br />
* private keys are often stored in a protected area of a microcontroller, and cannot be transferred out of the device in plaintext<br />
* immune to computer viruses that steal from software wallets<br />
* can be used securely and interactively, private keys never need to touch potentially-vulnerable software<br />
* much of the time, the software is open source, allowing a user to validate the entire operation of the device<br />
<br />
This page is an attempt to summarize all the known developments of hardware wallets that can use Bitcoin as part of their operation.<br />
<br />
== Security risks ==<br />
<br />
To date there have been no verifiable incidents of Bitcoins stolen from hardware wallets. Hardware wallets are relatively new, but at least for the time being they have maintained a good track record, unlike the numerous incidents of Bitcoin theft from Internet-connected computers.<br />
<br />
However, it's important to understand that hardware wallets are a high value target and depend on various assumptions holding true to maintain security. They are not a silver bullet, and there are several realistic ways in which a hardware wallet can fail to protect your Bitcoin. These risks need to be carefully considered when deciding how much trust to place in a hardware wallet, and which hardware wallet to buy.<br />
<br />
How a hardware wallet could fail to protect your Bitcoin:<br />
<br />
# '''Malware swaps recipient Bitcoin addresses''': a hardware wallet won't protect you from being tricked into sending Bitcoin to the wrong address. For example, malware on a PC could monitor for high value transactions and then swap out the recipient's authentic Bitcoin address for an address controlled by the attacker. When the stakes are high, multi factor (e.g., over the phone) confirmation of a recipient's Bitcoin address is recommended.<br />
# '''Insecure RNG ([https://en.wikipedia.org/wiki/Random_number_generation Random Number Generator])''': hardware wallets rely on the security of an RNG, often embedded in hardware, to generate your wallet's private keys securely. Unfortunately, it is notoriously difficult to verify the true randomness of the RNG. An insecure RNG may create wallet keys that can later be recreated by an attacker, by generating psuedo-randomness that would seem statistically indistinguishable from true randomness yet still be predictable to an advanced attacker. An RNG may become insecure as a result of malicious weakening or an unintentional mistake. This failure mode is common to any wallet generation procedure in which the true randomness of the source of entropy being used can not be verified.<br />
# '''Imperfect implementation''': the security of all computing devices relies on the quality of their implementation. Hardware wallets are no exception. Bugs at the software, firmware or hardware level may allow attackers to break into a hardware wallet and gain unauthorized access to secrets. Even if the design is perfect, proving the security of a hardware or software implementation is a very hard, mostly unsolved problem. To date, no wallet in existence is implemented using provably correct software.<br />
# '''Compromised production process''': even a perfect software and hardware implementation of a hardware wallet would be vulnerable to a corrupt production process that introduces intentional or unintentional holes into the final product. The introduction of hardware backdoors is a [https://www.wired.com/2016/06/demonically-clever-backdoor-hides-inside-computer-chip/ real concern] for high risk financial and military applications.<br />
# '''Compromised shipping process''': a compromised fulfillment process may substitute or modify secure devices for superficially identical but insecure replacements. Government programs that intercept hardware and modify them in route to insert backdoors [https://arstechnica.com/.../photos-of-an-nsa-upgrade-factory-show-cisco-router-getting-implant/ are known to exist].<br />
<br />
In summary:<br />
<br />
* While not a silver bullet hardware wallets can still be extremely useful, assuming you take care to use a good one: an authentic device manufactured by trustworthy, technically competent security experts with a good reputation (e.g., [[TREZOR]]).<br />
<br />
* [[Cold storage]] solutions implemented with open source software and general purpose hardware (e.g., [[BitKey]], Pi Wallet), using a verifiable source of entropy such as physical dice may provide superior security for some use cases (e.g., long term savings).<br />
<br />
== Connecting to a full node ==<br />
<br />
By default, most hardware wallets instruct the user to connect to the manufacturer's own web interface. The web page cannot steal the user's private keys but can spy on them or trick them into accept fake payments.<br />
<br />
Hardware wallets only keep the [[private keys]] safe and create spending transactions; they cannot tell you if you have actually received coins and in what quantity. Bitcoin's security model also requires that [[full node]] wallets are used. If not, somebody could pay you with a transaction of something other than bitcoin. If bitcoin is digital gold then a full node wallet is your own personal goldsmith who checks that the incoming payments are actually real. Also the third-party wallet will see all your [[Address|bitcoin addresses]] so this is very damaging to your privacy.<br />
<br />
Most hardware wallets can be connected to [[Electrum]] bitcoin wallet. Electrum can be connected to your own [[Electrum#Electrum Personal Server|full node via a server]]. <br />
<br />
See also: [[Full node#Why should you use a full node wallet]]<br />
<br />
== Commercial hardware wallets (ordered chronologically) ==<br />
<br />
=== [[Trezor|Trezor One]] ===<br />
[[File:Trezor-tx.jpg|300px|thumb|left|Confirming the transaction with Trezor]]<br />
<br />
[[Trezor]] is a secure bitcoin storage and a transaction signing tool with open source hardware and software. The private keys are generated by the device and never leave it thus they cannot be accessed by a malware.<br />
<br />
It uses a deterministic wallet structure which means it can hold an unlimited number of keys ([[BIP 0032]]/[[BIP 0044]]). A recovery seed is generated when the device is initialized. In case Trezor gets lost or stolen, all its contents can be recovered using this seed (private keys, bitcoin balance and transaction history) into a new device or another [[BIP 0039]]/[[BIP 0044]] compatible wallet. <br />
<br />
Trezor also introduced a unique way of PIN entering preventing keyloggers from recording it even when entered on a compromised computer. An encryption passphrase can be set on top of the PIN protection. More passphrases can be used for plausible deniability.<br />
<br />
Trezor One offers everything needed to protect cryptocurrency funds together with advanced features like [https://wiki.trezor.io/User_manual:Password_Manager Password manager] or [https://wiki.trezor.io/User_manual:Two-factor_Authentication_with_U2F U2F two-factor authorization]. <br />
<br />
''See also [[Hardware wallet#Trezor Model T|Trezor Model T - next-generation cryptocurrency hardware wallet]]''<br />
<br />
[https://shop.trezor.io Trezor E-shop] | [https://wiki.trezor.io Trezor Wiki] | [https://trezor.io Trezor Homepage]<br />
<br />
<br clear="all"><br />
<br />
=== KeepKey: Your Private Bitcoin Vault ===<br />
[[File:keepkey.jpg|300px|thumb|left|KeepKey showing a bitcoin transaction that needs to be manually approved.]]<br />
<br />
KeepKey is a USB device that stores and secures your bitcoins. When you entrust KeepKey with your money, each and every bitcoin transaction you make must be reviewed and approved via it's OLED display and confirmation button.<br />
<br />
KeepKey has a unique recovery feature utilizing a rotating cipher to restore private keys with a [[BIP 0039]] recovery seed. This means it is not necessary to store your private keys on KeepKey: the recovery process is secure enough so that KeepKey can be used as a transaction device for paper backups. <br />
<br />
[https://www.keepkey.com keepkey.com]<br />
<br />
<br clear="all"><br />
<br />
=== Opendime: Bitcoin Credit Stick ===<br />
<br />
[[file:Opendime.jpeg|300px|thumb|left|Opendime Package]]<br />
<br />
The 1st Bitcoin Bearer Bond or just call it a "Bitcoin Stick" <br />
<br />
Opendime is a small USB stick that allows you to spend Bitcoin like a dollar bill. Pass it along multiple times. <br />
Connect to any USB to check balance. Unseal anytime to spend online. Trust no one.<br />
<br />
It comes in the shape of a mini USB, and [[Opendime-ui.png|setting it up is astonishingly quick and simple]]. You plug OpenDime into a USB port, and it behaves just like a USB drive with a tiny amount of storage. In its folder, is a web page. You open the webpage in your browser, and there’s only one instruction to follow: “Drop a file onto the drive”. Once you do that, the OpenDime automagically generates a unique address for you to receive Bitcoin with.<br />
<br />
[http://www.opendime.com Opendime.com]<br />
<br />
* [https://opendime.com/#faq Opendime FAQ]<br />
* You can watch a [https://www.youtube.com/watch?v=9UFF9d3Y1BY video here]<br />
* Read this [https://medium.com/@beautyon_/exquisite-opendime-ad1195a2790e review]<br />
* Multi-language user interface: 中文 • 日本語 • English • Portuguese • Français • Deutsch • Русский<br />
* Works as USB drive with no need for software<br />
* [https://github.com/opendime/electrum Opendime Electrum plugin]<br />
* [https://github.com/opendime/ Opendime source files and key verification]<br />
<br />
<br clear="all"><br />
<br />
=== Coldcard: Ultra-secure Bitcoin Hardware Wallet ===<br />
<br />
[[file:Coldcard.png|300px|thumb|left|Coldcard Front and Back]]<br />
<br />
* Coldcard is an easy to use, ultra-secure, open-source and affordable hardware wallet that is easy to back up via an encrypted microSD card. Your private key is stored in a dedicated security chip. MicroPython software design allows you to make changes.<br />
* BIP39 based, which means you can backup the secret words onto paper, and have lots of sub-accounts and unlimited independent payment addresses. Now with BIP39 passphrase support, unlocking up to 5.9e197 additional wallets from the same seed words! It knows how to understand transactions, so you can see what you are approving.<br />
* The first "Partially Signed Bitcoin Transaction Format" - PSBT (BIP 174) native wallet which can be used completely offline for its entire lifecycle. See HWI for Bitcoin Core support!<br />
* True air-gap cold operation via MicroSD sneakernet or standard via USB<br />
<br />
[http://www.coldcardwallet.com Coldcardwallet.com]<br />
<br />
* [https://coldcardwallet.com/faq Coldcard FAQ]<br />
* [https://coldcardwallet.com/docs Coldcard Docs]<br />
* [https://github.com/coldcard/firmware Coldcard Source Code]<br />
<br />
<br clear="all"><br />
<br />
=== CoolWallet: The Ultimate Bitcoin Safe ===<br />
<!-- 2016-04-09: Consider removing this device until actually for sale? --><br />
<br />
[[File:CoolWallet in the box.jpeg|300px|thumb|left|CoolWallet showing Launch App, waiting for user to connect with smartphone via Bluetooth]]<br />
<br />
CoolWallet is a credit card sized Bluetooth device that stores and secures your bitcoins and private keys. It fits in your wallet and works wirelessly.<br />
<br />
Every Bitcoin transaction must be manually confirmed and approved through its e-paper display and button. <br />
<br />
CoolWallet only acknowledges the paired smartphone. Whoever stole the CoolWallet are not able to steal any bitcoins. Using recovery Seed can restore all your bitcoins in case you lost the device. <br />
<br />
[https://coolbitx.com coolbitx.com] | [https://github.com/CoolBitX-Technology/coolwallet-ios Source and specifications]<br />
<br />
<br clear="all"><br />
<br />
=== BlochsTech card: Your user friendly Bitcoin wallet ===<br />
<!-- 2016-04-09: Possible vaporware / scam? Website insecure & badly designed with no substantial info. Consider finding technical docs, real reviews or removing this device. --><br />
<br />
[[file:BlochsTech Bitcoin card hardware wallet.jpg|300px|thumb|left|Graphic printed on front of BlochsTech cards.]]<br />
<br />
The BlochsTech open Bitcoin card is an open protocol secure hardware Bitcoin wallet your grandmother could use.<br />
For shops it's faster to accept than slow QR code based wallets and more reliable as it works offline.<br />
<br />
Currently it's of course in a novelty phase like Casascius coins (of which thousands were sold),<br />
however in the long run it is fully capable of functionally replacing the VISA system in all nations.<br />
<br />
[http://www.BlochsTech.com BlochsTech.com]<br />
<br />
<br clear="all"><br />
<br />
<br />
<br />
=== BitLox Bitcoin Hardware Wallet ===<br />
[[file:Bitlox.jpg|300px|thumb|left|BitLox Bitcoin Hardware Wallet]]<br />
<br />
BitLox is a metal cased (aluminum or titanium) bitcoin hardware wallet that works with their own web based wallet by USB and apps for iPhone and Android using Bluetooth LE.<br />
<br />
At present it is the only bitcoin hardware wallet you can buy that works with iPhone. The device weighs one ounce and is the size of a credit card 4 mm thick.<br />
<br />
Bitlox allows you to set up hidden wallets. Unlike other hardware wallets your seed is never displayed on a connected computer or phone but only on the Bitlox. All your wallet, device and transaction PINs are only entered on the BitLox and never on any app. <br />
<br />
BitLox has also implemented several advanced security features not available on any other bitcoin hardware wallet. <br />
<br />
[http://www.bitlox.com bitlox.com]<br />
<br />
<br clear="all"><br />
<br />
<br />
=== Ledger Nano S - USB Smartcard Hardware Wallet ===<br />
[[File:ledger_wallet_nanos_photo.png|300px|thumb|left|Ledger Wallet Nano S]]<br />
<br />
Ledger Nano S is a secure Bitcoin hardware wallet. It connects to any computer through USB and embeds a built-in OLED display to double-check and confirm each transaction with a single tap on its buttons. It is architectured around a Secure Element (ST31 family) and built on top of the BOLOS platform, a powerful and flexible Operating System allowing the secure execution of multiple Open Source applications in full isolation.<br />
<br />
Main features:<br />
* cryptographic secrets protected by a secure chip<br />
* open source embedded Bitcoin app<br />
* Confirmation of transactions on the embedded screen<br />
* Built-in 4 digits PIN security lock<br />
* Built-in onboarding (seed generation and recovery)<br />
* BIP39 seed (12/18/24 words), easy backup and restoration<br />
* Multi-apps support: FIDO U2F, GPG, SSH…<br />
* USB connectivity<br />
* Foldable and compact casing<br />
<br />
[https://www.ledgerwallet.com/products/12-ledger-nano-s Ledger Nano S product page]<br />
<br />
<br clear="all"><br />
<br />
=== Secalot ===<br />
[[File:secalot_wallet.png|300px|thumb|left|Secalot]]<br />
<br />
Main features:<br />
* Software and hardware are fully open sourced.<br />
* Utilizes a secure microcontroller with a high performance dedicated cryptographic co-processor.<br />
* Integrates with the popular Electrum wallet.<br />
* PIN-code protected.<br />
* Confirm transactions with a touch button press on the device.<br />
* Supports P2PKH, P2SH, and segWit transactions.<br />
* Updatable firmware.<br />
* Extra functionality: OpenPGP smart card, FIDO U2F authenticator, one-time password generator.<br />
<br />
Website: [https://www.secalot.com www.secalot.com]<br />
<br />
<br clear="all"><br />
<br />
=== ELLIPAL - Airgapped hardware wallet with mobile support ===<br />
[[File:Ellipal wallet.png|300px|thumb|left|ELLIPAL]]<br />
<br />
ELLIPAL hardware wallet secures keys in cold storage without connections except for LCD screen. It works with companion mobile App via QR code.<br />
<br />
Main features:<br />
* Working with mobile phone via QR code<br />
* Internet Isolated Cold Wallet<br />
* Multi-currency, cross-chain<br />
* Supports P2PKH, P2SH, and segWit transactions<br />
* 4" Screen with touch panel<br />
* Support private key import<br />
* PIN-code and gesture pattern protect<br />
* Confirmation of transactions details on the screen<br />
* BIP32/BIP39/BIP44<br />
* iPhone and Android companion App: account management, market info and coin exchange. <br />
<br />
Website: [https://www.ellipal.com www.ellipal.com]<br />
<br />
<br clear="all"><br />
<br />
=== ELLIPAL Titan Cold Wallet ===<br />
[[File:Ellipaltitan.jpg|300px|thumb|left|ELLIPAL Titan]]<br />
<br />
ELLIPAL Titan is the upgraded version of the ELLIPAL EC01 hardware wallet. Main upgrades are within the hardware which improves protection against physical attacks while keeping absolute protection against remote attacks. ELLIPAL Titan works with ELLIPAL mobile App to secure and manage your cryptocurrency. Information is transferred between the cold wallet and App via QR code only.<br />
<br />
New additional features:<br />
* IP65 metal sealed frame - Light water jet & dust protection<br />
* Disassembly test: [https://www.youtube.com/watch?v=DuPcJudtd2o Video]<br />
* Fully isolated components, can never be connected to another device<br />
* USB port removed - no ports on the device<br />
* Anti-Tamper feature - data automatically deleted upon detection of a breach<br />
* Decentralized Finance functions and coin exchange [https://www.ellipal.com/pages/ellipal-cold-wallet-finance ELLIPAL Finance]<br />
* Verifiable and secure QR code [https://github.com/ELLIPAL?tab=repositories Github]<br />
<br />
ELLIPAL Titan Website: [https://www.ellipal.com/pages/ellipal-titan ELLIPAL Titan full info]<br />
<br />
<br clear="all"><br />
<br />
=== [[Trezor|Trezor Model T]] ===<br />
[[File:Trezor-model-t-photo-front.jpg|300px|thumb|left|Trezor Model T]]<br />
<br />
Trezor Model T is the premium version and next-generation cryptocurrency hardware wallet. In addition to the functionalities of Trezor One, it has a colored touchscreen for secure on-device input, modern design, an SD card slot, and some other more advanced features. <br />
For more information see [https://wiki.trezor.io/Trezor_Model_T Trezor Model T] and this [https://trezor.io/#comparison comparison table]<br />
<br />
[https://shop.trezor.io Trezor E-shop] | [https://wiki.trezor.io Trezor Wiki] | [https://trezor.io Trezor Homepage]<br />
<br />
<br clear="all"><br />
<br />
=== D'CENT Biometric Wallet - BLE enabled Hardware Wallet ===<br />
[[File:Dcent wallet photo.png|300px|thumb|left|D'CENT Biometric Wallet]]<br />
<br />
D'CENT Biometric Wallet is a secure multi-cryptocurrency hardware wallet. It connects by using Bluetooth or USB to any mobile devices. The wallet is based on multi-IC architecture built on Secure Element(EAL5+) embedded with the SecureOS to provide robust security for the secure execution of multiple wallet applications. <br />
<br />
Main features:<br />
* Cryptographic secrets protected by a secure chip<br />
* Large OLED (128x128) display for confirmation of transactions and QR Code for P2P transactions <br />
* Built-in biometric sensor for authentication and also supports the PIN <br />
* Built-in onboarding (seed and key generation in Secure Element)<br />
* BIP39 seed (24 words), easy backup and recovery<br />
* Easy and convenient FW update (no recovery is required after update)<br />
* Bluetooth and USB connectivity<br />
<br />
[https://dcentwallet.com D'CENT Wallet Homepage] | [https://medium.com/dcentwallet D'CENT on Medium] | [https://www.youtube.com/channel/UCKnYqiM3g3iaaAKcRZf-kbA D'CENT Youtube]<br />
<br />
<br clear="all"><br />
<br />
=== Cobo Vault - Air-gapped with QR code and Secure Element ===<br />
[[File:Vault_pro.png|300px|thumb|left|Cobo Vault Essential/Pro/Ultimate]]<br />
<br />
Cobo Vault is a completely air-gapped hardware wallet that uses verifiable QR codes to transmit transaction information back and forth with a mobile app. It houses an FIPS 140-2 Secure Element that uses four superimposed physical sources for true random number generation (TRNG). Private keys never leave the Secure Element when transactions are signed. Cobo Vault’s innovative Web Authentication process helps prevent supply chain attacks through double asymmetric encryption implementing our backend HSM server. Cobo Vault’s Secure Element’s BIP 32, 39, and 44 compliant firmware is open source ([https://github.com/CoboVault Github]).<br />
<br />
Cobo Vault Essential, Pro & Ultimate Features:<br />
* Air-gapped through auditable QR code data transmissions <br />
* Secure Element physical entropy private key generation and side-channel attack prevention<br />
* Open source Secure Element firmware (industry first) <br />
* Detachable battery (industry first) <br />
* MicroSD firmware upgrading<br />
* 4-inch touchscreen<br />
<br />
Cobo Vault Essential and Pro Features:<br />
* AAA battery support to prevent battery failure<br />
* Bitcon-only firmware version compatibility<br />
* Better camera for smoother QR code transactions<br />
* Features we will be adding (see the full product roadmap list in [https://medium.com/cobo-vault/second-gen-hardware-wallets-feature-support-c0aaf00a4216 our launch article])<br />
<br />
Cobo Vault Pro Features:<br />
* Fingerprint sensor for device unlock and transaction signing<br />
* Upgraded self-destruct mechanism <br />
* Rechargeable battery<br />
<br />
[https://cobo.com/hardware-wallet Cobo Vault Homepage] | [https://medium.com/cobo-vault Cobo Vault on Medium] | [https://shop.cobo.com Cobo Vault Shop]<br />
<br />
<br clear="all"><br />
<br />
=== BitBox02: Swiss made open source ===<br />
[[File:BitBox02.png.jpg|300px|thumb|left|BitBox02]]<br />
<br />
The BitBox02 is a Swiss made, fully open source hardware wallet that enables you to independently generate and securely store your private keys to access and transact crypto assets. It has a dual-chip design and the security architecture has been independently audited.<br />
<br />
* Easy backup and restore on microSD card<br />
* OLED display and invisible touch sensors<br />
* Plug in directly to computer/mobile with USB-C<br />
* USB-C to A adapter and extension cable included<br />
* Multiple cryptocurrency support: Bitcoin and [[altcoin]]s.<br />
* U2F function for secure logins<br />
* Bitcoin-only edition available; the limited firmware reduces the attack surface<br />
* BIP-39 compatible<br />
* Bech32 (Native segwit) compatible<br />
* Sleek and minimalist design<br />
* Made in Switzerland<br />
<br />
[https://shiftcrypto.ch/bitbox02 BitBox02 product page] | [https://github.com/digitalbitbox Source code]<br />
<br />
<br clear="all"><br />
<br />
== Not purchasable hardware wallets ==<br />
<br />
=== Ledger HW.1 - USB Smartcard Hardware Wallet ===<br />
[[File:Btchip_dongle.jpg|220px|thumb|left|HW.1 inserted in a laptop]]<br />
<br />
HW.1 is an implementation of a deterministic ([[BIP 0032]]) Hardware Wallet on a USB smartcard.<br />
<br />
It is typically used as a blind secure device for multi signature transactions - holding a set of derived private keys and signing transactions without requiring user confirmation.<br />
<br />
Power users can rely on it to confirm all transactions with a second factor scheme turning the dongle into a keyboard typing what the user is supposed to have signed, as a protection against malware.<br />
<br />
It is also possible to customize HW.1 for more specific needs, such as creating a prepaid card without revealing the deterministic seed before it is received by the user, or securing bitcoin transactions on a server.<br />
<br />
[https://www.ledgerwallet.com/products/3-ledger-hw-1 E-shop] | [https://ledgerhq.github.io/btchip-doc/bitcoin-technical.html Technical Documentation]<br />
<br />
<br clear="all"><br />
<br />
=== Ledger Nano - USB Smartcard Hardware Wallet ===<br />
[[File:ledger_wallet_photo.jpg|300px|thumb|left|Ledger Wallet USB]]<br />
<br />
Ledger Nano protects your Bitcoin data within a smartcard. Its micro-processor certified against all types of attacks (both physical and logical), and has been used in the banking industry for decades (think credit card chips). The device connects to your computer through the USB port and will do all the Bitcoin cryptographic heavy lifting such as signing transactions inside its secure environment. You can therefore use your Bitcoin account with maximum trust, even on an insecure or compromised computer.<br />
<br />
The second factor verification of the transaction signature can be done either with a paired smartphone (Android, iOS) or a physical security card.<br />
<br />
The Ledger Wallet Chrome application (available also on Chromium) provides an easy onboarding as well as a seamless user experience, and the Nano is compatible with numerous third party software: [[Electrum]], [[Mycelium]], [[GreenAddress]], Greenbits, [[Coinkite]] and Copay.<br />
<br />
[https://www.ledgerwallet.com/products/1-ledger-nano Ledger Nano product page] | [https://github.com/LedgerHQ Source and specifications]<br />
<br />
<br clear="all"><br />
<br />
=== Ledger Unplugged - NFC Smartcard Hardware Wallet ===<br />
[[File:ledger_unplugged_photo.jpg|300px|thumb|left|Ledger Unplugged NFC]]<br />
<br />
The Ledger Unplugged is a credit card sized NFC hardware wallet. It embeds an open source Java Card app and is compatible with all NFC enabled Android phones.<br />
<br />
The device can be used with Mycelium or Greenbits. In case of loss, you can restore it on any Ledger Wallet (Nano or another one) or all other compatible solutions (BIP 39).<br />
<br />
[https://www.ledgerwallet.com/products/6-ledger-unplugged Ledger Unplugged product page] | [https://github.com/LedgerHQ/ledger-javacard Source code]<br />
<br />
<br clear="all"><br />
<br />
=== BWALLET TREZOR clone ===<br />
<br />
[[File:BWALLET_Trezor_Clone.jpeg|200px|thumb|left|Chinese clone of Trezor]]<br />
<br />
BWALLET is a clone of Trezor by a Chinese company.<br />
Trezor code is open source and this device operates like a Trezor.<br />
However, this product has been [https://www.reddit.com/r/Bitcoin/comments/2tyier/bwallet_review_by_trezor_developer/ reviewed by Marek aka Slush(Trezor developer)] and he has found some problems which makes this device less than 100% compatible, for example it doesn't work with [http://mytrezor.com myTREZOR.com] website and it does not work with Trezor official firmware. <br />
<br />
[http://mybwallet.com MyBWALLET.com] | [http://www.bidingxing.com/en/bwallet Buy BWALLET]<br />
<br />
<br clear="all"><br />
<br />
=== Pi Wallet - cold storage ===<br />
[[File:Piwallet.jpeg|300px|thumb|left|Pi-Wallet]]<br />
<br />
The Pi-Wallet is a small computer with the [[Armory]] bitcoin client.<br />
<br />
Transactions are signed offline, then transferred on a USB stick via [https://en.wikipedia.org/wiki/Sneakernet Sneakernet] to an online system for broadcasting.<br />
<br />
[https://www.pi-wallet.com/ pi-wallet.com]<br />
<br />
<br clear="all"><br />
<br />
=== BitcoinCard Megion Technologies-Card based wallet ===<br />
[[File:Bitcoincard-medley-large.jpg|400px|thumb|left|Bitcoin Card]]<br />
[http://www.bitcoincard.org/ Bitcoincard Home Page]<br />
<br />
[http://blog.bitinstant.com/blog/2012/6/19/our-discovery-in-vienna-the-bitcoin-card.html Excellent review by evoorhees]<br />
<br />
Incorporates a e-paper display, keypad, and radio (custom ISM band protocol.) Unfortunately it is fairly limited in terms of transaction I/O, requiring a radio gateway or another bitcoincard wherever funds need to be transferred.<br />
<br />
<br clear="all"><br />
<br />
=== BitSafe - allten/someone42's hardware wallet ===<br />
[[File:Bitsafe-wallet-sizecompare.jpg|200px|thumb|left|Bitsafe wallet]]<br />
[https://bitcointalk.org/index.php?topic=152517.0 Final BitSafe announcement]<br />
<br />
Signing transactions only, requires USB host software for transactions & USB power. Has a OLED display and Confirm/Cancel buttons. Evolved out of someone42's prototype below, and has significant contributions from someone42 as well.<br />
<br clear="all"><br />
<br />
=== Swiss Bank in Your Pocket - Hardware wallet ===<br />
[[File:SBIYP.png|300px|thumb|left|Swiss Bank In Your Pocket]]<br />
<br />
The Swiss Bank in Your Pocket is a Windows Desktop Application providing functionality for 5 Bitcoin Wallets and a Bitcoin Vault. <br />
<br />
The Bitcoin Vault can only send Bitcoins to the Bitcoin Wallets with in the application. Each Bitcoin wallet can have up to 5 Receive addresses. The intuitive user interface is designed for ease of use. USB security key is required to make any type of transaction. frontend software is installed on windows. Package includes secure USB key, and an additional recovery USB key. So in case of an accident, customer will have an additional backup to access their wallets. <br />
<br />
[https://swissbankinyourpocket.com/ swissbankinyourpocket.com]<br />
<br />
<br clear="all"><br />
<br />
=== BitBox 01 (Digital Bitbox) ===<br />
[[file:Digital-bitbox.png|thumb|left|Digital Bitbox Hardware Wallet]]<br />
<br />
* Secure hardware RNG & key storage using [http://www.atmel.com/Images/Atmel-8914-CryptoAuth-ATAES132A-Datasheet.pdf crypto element] with 50 year lifespan and an epoxy-filled case.<br />
* Offline backup and recovery of [[BIP_0032|BIP-32]] seed with a micro SD card rather than [[BIP_0039|BIP-39]] phrase written on paper as in Trezor.<br />
* Native software wallet client and ability to use a mobile phone for 2FA and to verify transaction details.<br />
* Multisig out-of-the-box including Copay support.<br />
* [https://github.com/digitalbitbox Open Source] ([https://github.com/digitalbitbox/mcu#digital-bitbox-firmware firmware], [https://github.com/digitalbitbox/mcu/blob/bf48984fd4a47d9ebf6814f7d01b078964587c7c/src/bootloader.c bootloader], [https://github.com/digitalbitbox/dbb-app desktop client]).<br />
* Full FIDO U2F support (https://en.wikipedia.org/wiki/Universal_2nd_Factor)<br />
* Made in Switzerland (a country with strong privacy laws) by [[Bitcoin Core]] developer Jonas Schnelli.<br />
<br />
[https://digitalbitbox.com digitalbitbox.com]<br />
<br />
<br clear="all"><br />
<br />
=== someone42's original prototype ===<br />
[[File:Someone42-wallet-prototype.jpg|300px|thumb|left|someone42's original prototype]]<br />
[https://bitcointalk.org/index.php?topic=78614.0 Hardware Bitcoin wallet - a minimal Bitcoin wallet for embedded devices]<br />
<br />
Signing transactions only, requires USB host software for transactions & USB power. All work is rolled into the above BitSafe wallet currently.<br />
<br clear="all"><br />
=== Other/Defunct but with good discussion: ===<br />
* natman3400's BitClip Jun 2011 [https://bitcointalk.org/index.php?topic=24852.0 https://bitcointalk.org/index.php?topic=24852.0]<br />
:Seems to have gone defunct around Dec 2011. Some good ideas though and seemed to have started on execution.<br />
* jim618 hardware wallet proposal Apr 2012 [https://bitcointalk.org/index.php?topic=77553.0 Dedicated bitcoin devices - dealing with untrusted networks]<br />
:Great discussion and good ideas from jim618. Also linked the following video:<br />
* Prof. Clemens Cap's hardware wallet? (video:)[https://www.youtube.com/watch?v=IavQ-Wc8S1U Clemens Cap about electronic bitcoin wallet at EuroBit]<br />
:Clemens Cap of Uni Rostock explains the Electronic Bitcoin wallet device he's working on. It's based on adafruit microtouch device.<br />
* ripper234's discussion based on Yubikeys Aug 2012 [https://bitcointalk.org/index.php?topic=99492 Having a YUBIKEY as one of the parties for m-of-n signatures]<br />
:The use of Yubikeys. They only support symmetric crypto, so you'd have to trust the host device.<br />
* kalleguld's hardware wallet proposal Oct 2012 [https://bitcointalk.org/index.php?topic=115294.0 Proposal: Hardware wallet (Win 3 BTC)]<br />
* Vaporware: Matthew N Wright's ellet [https://bitcointalk.org/index.php?topic=85931.0 ANN The world's first handheld Bitcoin device, the Ellet!] (Vaporware)<br />
<br />
== Smart Card based wallets ==<br />
This type of device requires complete trust in the host device, as there is no method for user input.<br />
See [[Smart card wallet]]<br />
<br />
== Related Resources ==<br />
* [https://bitcoinnewsmagazine.com/best-bitcoin-hardware-wallet-2015/ Best Bitcoin Hardware Wallet 2015] - reviews of all bitcoin hardware wallets.<br />
* [http://99bitcoins.com/trezor-vs-ledger-hands-hardware-wallets-review/ TREZOR vs. Ledger] - User reviews and Reddit feedback<br />
* [https://bitcointalk.org/index.php?topic=125383.0 Hardware wallet wire protocol]: slush's Hardware wallet wire protocol discussion<br />
* [https://bitcointalk.org/index.php?topic=19080.msg272348#msg272348 Re: Split private keys]: kjj's Todo List discussion for client protocol requirements<br />
* [https://bitcointalk.org/index.php?topic=134277.0 Hardware Wallet Roundup]<br />
* [https://www.buybitcoinworldwide.com/wallets/ Bitcoin Hardware Wallet Comparison] - information about using Bitcoin hardware wallets for cold storage.<br />
* [https://www.weusecoins.com/bitcoin-ledger-wallet-review/ Ledger Wallet Review]<br />
<br />
== See Also ==<br />
<br />
* [[Storing bitcoins]]<br />
* [[How to set up a secure offline savings wallet]]<br />
* [[Cold storage]]<br />
<br />
[[Category:Security]]<br />
[[Category:Wallets| ]]<br />
[[Category:Hardware]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Firi&diff=68089Firi2020-07-28T13:13:37Z<p>Furunodo: </p>
<hr />
<div>{{infobox company|name=MiraiEx, Inc.|image=[[File:Miraiex.png]]<br />
|industry=[[eWallet]], [[exchange]]<br />
|founder=Thuc Hoang, Øyvind Kvanes,<br />
|foundation=June 01, 2017<br />
|location=Oslo, Norway<br />
|twitter=Mirai_Exchange<br />
|facebook=MiraiExchange<br />
|<br />
|website=[https://miraiex.com/ Miraiex.com]}}'''MiraiEx''' is a Norwegian crypto currency exchange, which allows users to exchange NOK for bitcoin and [[altcoin]]s. Users can connect their Norwegian bank account to the exchange and deposit funds with express payments.<br />
<br />
The service is currently limited to Norwegian citizens. All users must have a personal identification number issued by the Norwegian government.<br />
<br />
==Exchange==<br />
MiraiEx was founded in 2017, becoming one of the earliest cryptocurrency exchanges to enter the Norwegian market. In 2019 it registered with the Norwegian Financial Authority (Finanstilsynet), as an exchange service for digital currencies.<br />
<br />
===Buy Bitcoin===<br />
<br />
Miraiex allows traders to buy bitcoin with the help of either NOK (Norwegian kroner), or [[altcoin]]s. It has an open-end API for high volume traders that wish to act as market makers.<br />
<br />
==Informational links==<br />
<br />
[https://miraiex.com/no/fees Fees info] Information on fees for deposits, withdrawals and exchange.<br />
<br />
[https://developers.miraiex.com/ API documentation] API instructions for custom applications and how to connect with the exchange service.<br />
<br />
==Fees for trading==<br />
<br />
Miraiex charges a flat fee of 0,5% for both sale and buy orders. Users are granted a 5% cashback with each trade which is refunded at the end of the month.<br />
<br />
Bank deposits and withdrawals are free.<br />
<br />
==History and background==<br />
<br />
MiraiEx was conceptualized and founded in 2017, with the first beta version of the service going live in 2018. Founders include Øyvind Kvanes and Thuc Hoang.<br />
<br />
An integral part of its service is the ability to buy bitcoin and other cryptocurrencies with the help of "fast payments", in which transfers are credited within 60 minutes. <ref>[https://www.xn--privatkonomi-0jb.net/kryptovalutab%C3%B8rs/miraiex/ MiraiEx Vurdering - Privatøkonomen]</ref>.<br />
<br />
==External Links==<br />
<br />
* [https://miraiex.com/ MiraiEx.com] website<br />
<br />
==References==<br />
<references/><br />
<br />
[[Category:Exchanges]]<br />
[[Category:Services]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=BitcoinTrade&diff=68088BitcoinTrade2020-07-28T13:13:21Z<p>Furunodo: altcoins</p>
<hr />
<div>A Brazilian cryptocurrency exchange where users can buy or sell Bitcoin and [[altcoin]]s.<br />
<br />
The currency supported is BRL (Brazilian Real).<br />
<br />
==History==<br />
<br />
The service was launched on October 16, 2017. <ref>[https://cointimes.com.br/exchange/bitcointrade/ BitcoinTrade, exchange de bitcoins brasileira]</ref> <br />
<br />
In 2020, it was considered the 61th biggest cryptocurrency exchange company in the world according to CoinMarketCap<ref>[https://livecoins.com.br/mercado-bitcoin-e-uma-das-15-maiores-corretoras-do-mundo-coinmarketcap/ Mercado Bitcoin é uma das 15 maiores corretoras do mundo, de acordo com o CoinMarketCap]</ref>. Considering only the brazilian market, it's the second biggest one, right after [https://en.bitcoin.it/wiki/Mercado_Bitcoin Mercado Bitcoin].<br />
<br />
==See Also==<br />
<br />
* [[:Category:Exchanges|Exchanges]]<br />
<br />
==External Links==<br />
<br />
* [https://www.bitcointrade.com.br/pt-BR/ BitcoinTrade.com.br] website<br />
<br />
==References==<br />
<br />
<references /><br />
<br />
<br />
[[:Category:Companies]]<br />
[[:Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Blockmove.io&diff=68087Blockmove.io2020-07-28T13:12:41Z<p>Furunodo: /* Features of Blockmove */</p>
<hr />
<div>{{infobox company|name=Blockmove Inc.|image=[[File:Blocklogo.jpeg|256px]]<br />
<br />
|industry=[[:Category:Payment Processors | Payment Processor]], [[eWallet]], [[Exchange]]<br />
|foundation=June, 2019<br />
|founder=[[Alex Gruber]], [[Serge Olsen]]<br />
|employees=10+<br />
|twitter=blockmove_io<br />
|website=https://blockmove.io/<br />
}}<br />
<br />
https://blockmove.io/ '''Blockmove.io''' excels at making great products that bring the benefits of digital currency to everyone. It requires us to be world class at security, technology, customer support, design and as service provider. We are making a breakthrough in the field of accepting cryptocurrency on your website. We challenge the status quo and transcend the boundaries of today to create an open financial future that supports the broadest global community. <br />
<br />
==Features of Blockmove==<br />
<br />
''During the development process of their product, the Blockmove creators put its users` privacy and the security of their funds at the forefront.''<br />
<br />
''Based on these provisions, the Blockmove crypto wallet received the following characteristics:''<br />
<br />
'''Anonymity'''. Its users do not go through the KYC procedure, but only leave their email address when registering. The service doesn`t require any more data.<br />
<br />
'''Security'''. Only the user has full control over the private keys. They are only available to the user when requested in the wallet.<br />
<br />
'''Large selection of supported cryptocurrencies'''. Bitcoin, [[altcoin]]s.<br />
<br />
'''Convenience'''. Simple and intuitive interface of the crypto wallet. Quick registration in a couple of minutes.<br />
<br />
'''Not only storage, but also exchange of cryptocurrencies'''. Its users can quickly and securely exchange digital assets without leaving their wallet.<br />
<br />
'''24/7 support'''. A professional support service provides assistance to the users throughout the entire time of using the wallet.<br />
<br />
==Merchant Tools==<br />
For merchants that already have a shopping cart, Blockmove Merchant can allow shoppers to pay for their order using bitcoins. <br />
For merchants that only have a catalog of items, Blockmove can provide buttons and widgets for merchants to place by their items, which will add them to a shopping cart at Blockmove. <br />
<br />
[https://blockmove.io/products/merchant Payment buttons] make it easy to accept bitcoin on any website by copying and pasting a few lines of code.<br />
<br />
Callbacks allow for instant payment notifications to a merchant's website.<br />
<br />
Blockmove also offers an [https://blockmove.io/products/api API] for custom applications or merchant integrations.<br />
<br />
==Fees==<br />
'''Merchant''' - you will be able to do this for '''free''' for a whole year, after '''$ 49 per month''' and no interest for each payment. <br />
<br />
When using the '''API''', you`ll pay only '''0.3% for withdrawal transaction''' – this is the minimum commission compared with similar services. <br />
<br />
==External Links==<br />
<br />
* [https://blockmove.io/ Blockmove.io] Website<br />
* [https://blockmove.io/products/api API] API Service<br />
* [https://blockmove.io/products/merchant Merchant] Online Payments<br />
* [https://wallet.blockmove.io/ Wallet] Blockmove Wallet<br />
* [https://t.me/blockmove_support Support] Telegram Support<br />
<br />
[[Category:Shopping Cart Interfaces]]<br />
[[Category:Payment Processors]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Gatecoin&diff=68086Gatecoin2020-07-28T13:12:27Z<p>Furunodo: </p>
<hr />
<div>Gatecoin is an international financial institution for digital currencies. Available for the moment is an [[currency exchange|exchange]] for trading bitcoins, [[altcoin]]s and several fiat currencies (USD, HKD, EUR).<br />
<br />
Gatecoin is Money-Service Operator licensed in Hong-Kong and incubated by the Hong-Kong Science Technology Parks (HKSTP) and Tsinghua University.<br />
<br />
<br />
==History==<br />
<br />
The online platform launched publicly in Q1 2015. Gatecoin is based in Hong Kong and operated by Gatecoin Ltd, incorporated on July 24th, 2013 in Hong Kong, SAR. Gatecoin won the 2014 Best Start-Up Prize for Central and East Asia at Talent Unleashed. Richard Branson and Steve Wozniak were part of the jury. Gatecoin co-founders are active members of the bitcoin community. Co-found and CEO Aurélien MENANT is one of the founding members of the Bitcoin Association of Hong Kong. Gatecoin regularly participates in conferences such as the Bitcoin Expo 2014 in Shanghai, the Inside Bitcoin conferences 2014 in Hong Kong, Paris 2014 and Singapore 2015.<br />
<br />
Gatecoin also created the website coincharities.org that works like Kickstarter that accepts donations in bitcoins.<br />
<br />
==Fees==<br />
<br />
Gatecoin offers 15 days of free trading for new users after making their first deposit. After that period, the fees depend on volumes and status:<br />
{| border="1" cellpadding="8" cellspacing="0"<br />
!Volume traded per month [BTC]<br />
!Fee* [%]<br />
|-<br />
|<20<br />
|0.35<br />
|-<br />
|<50<br />
|0.30<br />
|-<br />
|<100<br />
|0.25<br />
|-<br />
|<200<br />
|0.20<br />
|-<br />
|>200<br />
|0.15<br />
|-<br />
|}<br />
*Once you reach a threshold over a rolling 31 day period, the discounted fee is automatically applied to your following trades.<br />
<br />
{| border="1" cellpadding="8" cellspacing="0"<br />
!Account Type<br />
!Standard<br />
!Market Maker<br />
!Member<br />
|-<br />
|Minimal Trading Fees <br />
|0.15%<br />
|0.1%<br />
|0.05%<br />
|-<br />
|Account Pricing<br />
|Free<br />
|BTC 0.08/month<br />
|BTC 0.8/month<br />
|-<br />
|VIP Gateway<br />
|NO<br />
|YES<br />
|YES<br />
|-<br />
|VPN & FIX Access<br />
|NO<br />
|NO<br />
|YES<br />
|-<br />
|}<br />
For more detailed information, visit: https://gatecoin.com/public/feeschedule<br />
<br />
==See Also==<br />
<br />
* [[Buying bitcoins]]<br />
* [[Selling bitcoins]]<br />
<br />
==External Links==<br />
<br />
* [https://www.gatecoin.com Gatecoin.com] web site<br />
<br />
==References==<br />
<References /><br />
<br />
[[Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Blockmove&diff=68085Blockmove2020-07-28T13:12:04Z<p>Furunodo: /* Features of Blockmove */ altcoins</p>
<hr />
<div>{{infobox company|name=Blockmove Inc.|image=[[File:Blocklogo.jpeg|256px]]<br />
<br />
|industry=[[:Category:Payment Processors | Payment Processor]], [[eWallet]], [[Exchange]]<br />
|foundation=June, 2019<br />
|founder=[[Alex Gruber]], [[Serge Olsen]]<br />
|employees=10+<br />
|twitter=blockmove_io<br />
|website=https://blockmove.io/<br />
}}<br />
<br />
https://blockmove.io/ '''Blockmove.io''' excels at making great products that bring the benefits of digital currency to everyone. It requires us to be world class at security, technology, customer support, design and as service provider. We are making a breakthrough in the field of accepting cryptocurrency on your website. We challenge the status quo and transcend the boundaries of today to create an open financial future that supports the broadest global community. <br />
<br />
==Features of Blockmove==<br />
<br />
''During the development process of their product, the Blockmove creators put its users` privacy and the security of their funds at the forefront.''<br />
<br />
''Based on these provisions, the Blockmove crypto wallet received the following characteristics:''<br />
<br />
'''Anonymity'''. Its users do not go through the KYC procedure, but only leave their email address when registering. The service doesn`t require any more data.<br />
<br />
'''Security'''. Only the user has full control over the private keys. They are only available to the user when requested in the wallet.<br />
<br />
'''Large selection of supported cryptocurrencies'''. Bitcoin, [[altcoin]]s.<br />
<br />
'''Convenience'''. Simple and intuitive interface of the crypto wallet. Quick registration in a couple of minutes.<br />
<br />
'''Not only storage, but also exchange of cryptocurrencies'''. Its users can quickly and securely exchange digital assets without leaving their wallet.<br />
<br />
'''24/7 support'''. A professional support service provides assistance to the users throughout the entire time of using the wallet.<br />
<br />
==Merchant Tools==<br />
For merchants that already have a shopping cart, Blockmove Merchant can allow shoppers to pay for their order using bitcoins. <br />
For merchants that only have a catalog of items, Blockmove can provide buttons and widgets for merchants to place by their items, which will add them to a shopping cart at Blockmove. <br />
<br />
[https://blockmove.io/products/merchant Payment buttons] make it easy to accept bitcoin on any website by copying and pasting a few lines of code.<br />
<br />
Callbacks allow for instant payment notifications to a merchant's website.<br />
<br />
Blockmove also offers an [https://blockmove.io/products/api API] for custom applications or merchant integrations.<br />
<br />
==Fees==<br />
'''Merchant''' - you will be able to do this for '''free''' for a whole year, after '''$ 49 per month''' and no interest for each payment. <br />
<br />
When using the '''API''', you`ll pay only '''0.3% for withdrawal transaction''' – this is the minimum commission compared with similar services. <br />
<br />
==External Links==<br />
<br />
* [https://blockmove.io/ Blockmove.io] Website<br />
* [https://blockmove.io/products/api API] API Service<br />
* [https://blockmove.io/products/merchant Merchant] Online Payments<br />
* [https://wallet.blockmove.io/ Wallet] Blockmove Wallet<br />
* [https://t.me/blockmove_support Support] Telegram Support<br />
<br />
[[Category:Shopping Cart Interfaces]]<br />
[[Category:Payment Processors]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Utorg&diff=68084Utorg2020-07-28T13:11:33Z<p>Furunodo: altcoins</p>
<hr />
<div>{{infobox company|name=Utorg Crypto Exchange|image=[[File:Utorg-main.png|275px]]<br />
|trading_name=Utorg.io<br />
|industry=[[Exchange|Bitcoin exchange]]<br />
|foundation=2018<br />
|currencies=BTC, [[altcoin]]s, USDT, USD, RUB, UAH<br />
|website=https://utorg.io<br />
}}<br />
<br />
==UTORG.IO==<br />
'''Utorg''' is a cryptocurrency exchange, where you can easily buy, sell and trade Bitcoins and [[altcoin]]s directly with fiat currencies such as RUB, UAH, USD. Utorg offers large selection of fiat gateways, including Advcash, Qiwi, Payeer. Perfect Money, Visa/Mastercard, Wire transfer. <br />
<br />
Lowest fees on the market: <br />
- Fiat deposit fees start from 0,5%;<br />
- Maker fee is 0%, and taker fee 0.2%.<br />
'''Utorg''' also acts as a service-provider for many businesses, which connect to Utorg and use the proprietary software developed in-house to automate processing of crypto and fiat, mostly exchangers and e-commerce services.<br />
For business and listing requests, please contact support@utorg.io<br />
<br />
==Deposit/Withdraw Funds==<br />
<br />
===Fiat currencies===<br />
* USD<br />
* RUB<br />
* UAH<br />
<br />
===Crypto currencies===<br />
* BTC<br />
* [[altcoin]]s<br />
* USDT (ERC20)<br />
<br />
=== [https://utorg.io/fees Full list of fees and limits on Utorg] <ref>[https://utorg.io/fees Utorg.io Fees and Limits]</ref> ===<br />
<br />
<br />
==Services==<br />
<br />
The exchange launched publicly in August 2019, offering following trading pairs: RUB/BTC, RUB/ETH, UAH/BTC, UAH/ETH<ref>[https://bitcointalk.org/index.php?topic=5171499.0 Utorg.io - Exchange Now Open with Live Trading BTC, ETH, RUB, USD]</ref><ref>[https://www.bitcoinminershashrate.com/utorg-exchange-started-beta-testing/ Utorg Exchange Started Beta Testing]</ref>.<br />
<br />
===Instant Change===<br />
Secure and fast conversion of cryptocurrencies to fiat currencies and back in 1 click. <br />
<br />
===Exchange Platform===<br />
Trading terminal to trade crypto currencies. [https://utorg.io/trade Utorg Exchange]<br />
<br />
===IOU DESK===<br />
IOU Desk – is a digital market platform where users are able to buy and sell project tokens before these projects go public. The tokens were acquired at the various financing stages, starting from seed rounds and finishing with ICOs. They have a number of forms: IOU (I owe you) – debt documents, agreements, SAFTs, and others. First IOU was conducted for PERLIN project<ref>[https://medium.com/@QB_community/on-the-utorg-exchange-iou-trading-on-perlin-begins-29fec7ff7499 On the Utorg exchange, IOU trading on Perlin begins]</ref><br />
<br />
===UTORG PRO===<br />
Merchant as a SaaS solution for exchangers, eCommerce and other payment platforms<br />
<br />
===API===<br />
Full-fledged API<ref>[https://static.utorg.io/docs/index.html#general-info Utorg Exchange API Documentation]</ref>, allowing to connect to Utorg and integrate third-party services to use data from Utorg Exchange<br />
<br />
==Referral Program==<br />
<br />
Within [https://utorg.io/referral Utorg Exchange Referral Program]<ref>[https://utorg.io/referral Utorg Referral Program]</ref>, users get 20% of fee from all exchange transactions of their referred users. UTORG.IO offers promotional tools, statistics and instant withdrawals of Referral rewards. Min amount of rewards to withdraw is $10. <br />
<br />
==Utorg advantages==<br />
* Convenient tools for miners and business<ref>[https://blockchainjournal.news/utorg-cryptocurrency-exchange-supporting-fiat-currencies-targets-miners/ Utorg Targets Miners]</ref>;<br />
* Wide selection of payment instruments;<br />
* IOU - trade future tokens;<br />
* Ease of registration;<br />
* Ease of verification;<br />
* Simple and intuitive interface;<br />
* High security;<br />
* 2FA option;<br />
* Round-the-clock support;<br />
* Multisig Wallets;<br />
* SegWit support<br />
<br />
==See Also==<br />
<br />
* [[Exchanges]]<br />
<br />
==External Links==<br />
<br />
* [http://utorg.io Utorg.io] website<br />
<br />
==References==<br />
<References /><br />
<br />
[[Category:Exchanges]]<br />
[[Category:Local]]<br />
[[Category:Mining_contractors]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Comparison_of_cryptocurrencies&diff=68083Comparison of cryptocurrencies2020-07-28T13:10:47Z<p>Furunodo: removing links to scamcoins</p>
<hr />
<div>The cryptocurrency market is explosive which currently serves hundreds of currencies. Almost all of them are obvious scams—including many which purport to have a large market cap. This article aims to list only the most relevant cryptocurrencies in terms of novel technological advancements or strong engineering teams, or due to widespread awareness thereof. Direct, low-level scams should not be listed here.<br />
<br />
{| class="wikitable sortable"<br />
! style="width: 100px;" | Cryptocurrency<br />
! Exchange symbol<br />
! Launched<br />
! Anonymity<br />
! Max supply<br />
! Algorithm<br />
! Proof Type<br />
! Notes<br />
! Website<br />
|-<br />
! {{rh}} | [[File:Bitcoin.png|16px|link=]] [[Bitcoin]]<br />
| BTC<br />
| 2009-01-03<br />
| {{no|Low}}<br />
| style="text-align: right" | ~21,000,000<br />
| SHA256<br />
| PoW<br />
| First blockchain.<br />
| [https://bitcoin.org/ bitcoin.org]<br />
|-<br />
! {{rh}} | [[File:Bitcoin.png|16px|link=]] [[Tonal Bitcoin]]<br />
| TBC<br />
| 2011-01-02<br />
| {{no|Low}}<br />
| style="text-align: right" | ~21,000,000<br />
| SHA256<br />
| PoW<br />
| First on-chain alternative.<br />
| -<br />
|-<br />
! {{rh}} | [[File:Bitcoin_Cash.png|16px|link=]] BCash<br />
| BCH<br />
| 2017-08-01<br />
| {{no|Low}}<br />
| style="text-align: right" | ~21,000,000<br />
| SHA256<br />
| PoW<br />
| BCash is an altcoin based on an old snapshot of Bitcoin's blockchain (2017 Aug 1) with replay protection and an increased block size limit of 8MB. An unusual emergency difficulty adjustment algorithm causes significant periods of hyperinflation. Significant miner centralization; often a very low hashrate. Major proponents deliberately attempt to confuse new users into thinking BCash is actually Bitcoin, especially by using the name "Bitcoin Cash". On 15 November 2018, an airdrop of BCash occurred between two rival factions now called BCash (BCH) and CraigCoin (BSV).<br />
| [https://www.bitcoincash.org/ bitcoincash.org]<br />
|-<br />
! {{rh}} | [[File:Bitcoin.png|16px|link=]] CraigCoin<br />
| BSV<br />
| 2018-11-15<br />
| {{no|Low}}<br />
| style="text-align: right" | ~21,000,000<br />
| SHA256<br />
| PoW<br />
| On 15 November 2018, a hard fork chain split of BCash occurred between two rival factions called BCH and BSV. Mostly based around a cult following of the fraudster Craig Wright who claims to be Satoshi (hence SV = Satoshi's Vision).<br />
| https://bitcoinsv.io/<br />
|-<br />
! {{rh}} | [[File:Namecoin.png|16px|link=]] Namecoin<br />
| NMC<br />
| 2011-04-18<br />
| {{no|Low}}<br />
| style="text-align: right" | ~21,000,000<br />
| SHA256 Merged<br />
| PoW<br />
| First cryptocurrency that implemented Satoshi's BitDNS idea. Essentially the first real altcoin. Still under active development. First merged-mined altcoin.<br />
| [https://namecoin.info/ namecoin.info]<br />
|-<br />
! {{rh}} | [[File:Dash.png|16px|link=]] Dash<br />
| DASH<br />
| 2014-01-18<br />
| {{no|Low}}<br />
| style="text-align: right" | 22,000,000<br />
| X11<br />
| PoW/PoS<br />
| Introduced the X11 algorithm, which is just a composite function of multiple hashing algorithms. Had a significant failure mode in the beginning which equated to a majority premine by a small number of Amazon EC2 customers. This means their Master Node algorithm has been in a failure mode from the beginning.<br />
| [https://dash.org/ dash.org]<br />
|-<br />
! {{rh}} | [[File:Ethereum_Classic-32x32.png|16px|link=]] Ethereum Classic<br />
| ETC<br />
| 2015-08-07<br />
| {{no|Low}}<br />
| style="text-align: right" | Infinite<br />
| Ethash<br />
| PoW<br />
| Majority premine sale. Used to be known as just "Ethereum" and "ETH" until the Ethereum Foundation split off an altcoin using their trademark.<br />
| [http://www.ethereumclassic.org/ ethereumclassic.org]<br />
|-<br />
! {{rh}} | [[File:Ethereum.png|16px|link=]] Ethereum<br />
| ETH<br />
| 2016-07-20<br />
| {{no|Low}}<br />
| style="text-align: right" | Infinite<br />
| Ethash<br />
| PoW<br />
| An altcoin of Ethereum Classic which split from ETC's blockchain in order to refund the Ethereum Foundation's members' money when the DAO was exploited. Regular hardforks to bail out larger losses by e.g. ETH foundation. Source of the ICO bubbles. Multiple client implementations which fail against each other in terms of consensus errors regularly. Requires multiple months of time to sync to eth blockchain. Contract-building tools interpret input incompatibly.<br />
| <br />
|-<br />
! {{rh}} | [[File:Litecoin.png|16px|link=]] Litecoin<br />
| LTC<br />
| 2011-10-07<br />
| {{no|Low}}<br />
| style="text-align: right" | ~84,000,000<br />
| Scrypt<br />
| PoW<br />
| Originally meant to be a CPU-friendly "silver" to Bitcoin's "gold", the early SCRYPT parameters, it was discovered later, led directly to GPU, and then ASIC-mining almost from the start.<br />
| <br />
|-<br />
! {{rh}} | [[File:Monero.png|16px|link=]] Monero<br />
| XMR<br />
| 2014-04-18<br />
| {{yes|High}} <br />
| Infinite (has tail emission of 0.6 XMR)<br />
| [https://github.com/tevador/RandomX RandomX] (formerly [[CryptoNight]])<br />
| PoW<br />
| The most successful implementation derived from the [[CryptoNote]] codedrop. Uses [https://www.ledgerjournal.org/ojs/index.php/ledger/article/view/34 Ring CT] and its own implementation of [[Confidential transactions]], [[ECDH_address|Stealth Addresses]], [[BIP_0156|Dandelion]]++ to enhance user privacy.<br />
| [https://getmonero.org/ getmonero.org]<br />
|-<br />
! {{rh}} | [[File:Zcash-16x16.png|16px|link=]] Zcash<br />
| ZEC<br />
| 2016-10-28<br />
| style="background: lightyellow;text-align: center;" | Medium<br />
| style="text-align: right" | ~21,000,000<br />
| Equihash<br />
| PoW<br />
| First cryptocurrency that implemented the zerocash protocol. Large "Founder's Reward" which is paid out over the first few years of mining to people including Roger Ver.<br />
| [https://z.cash/ z.cash]<br />
|-<br />
! {{rh}} | [[File:Zcoin-800x800.png|16px|link=]] Zcoin<br />
| XZC<br />
| 2016-09-28<br />
| style="background: lightyellow;text-align: center;" | Medium<br />
| style="text-align: right" | ~21,000,000<br />
| Lyra2RE<br />
| PoW<br />
| First cryptocurrency that implemented the zerocoin protocol which also makes it the first useful Zero-knowledge proof based anonymous cryptocurrency. First that implements Merkle Tree Proof of Work (MTP).<br />
| <br />
|-}<br />
<br />
[[Category:Alternative cryptocurrencies]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Firi&diff=68082Firi2020-07-28T13:09:46Z<p>Furunodo: </p>
<hr />
<div>{{infobox company|name=MiraiEx, Inc.|image=[[File:Miraiex.png]]<br />
|industry=[[eWallet]], [[exchange]]<br />
|founder=Thuc Hoang, Øyvind Kvanes,<br />
|foundation=June 01, 2017<br />
|location=Oslo, Norway<br />
|twitter=Mirai_Exchange<br />
|facebook=MiraiExchange<br />
|<br />
|website=[https://miraiex.com/ Miraiex.com]}}'''MiraiEx''' is a Norwegian crypto currency exchange, which allows users to exchange NOK for bitcoin and [[altcoin]]s. Users can connect their Norwegian bank account to the exchange and deposit funds with express payments.<br />
<br />
The service is currently limited to Norwegian citizens. All users must have a personal identification number issued by the Norwegian government.<br />
<br />
==Exchange==<br />
MiraiEx was founded in 2017, becoming one of the earliest cryptocurrency exchanges to enter the Norwegian market. In 2019 it registered with the Norwegian Financial Authority (Finanstilsynet), as an exchange service for digital currencies.<br />
<br />
===Buy Bitcoin===<br />
<br />
Miraiex allows traders to buy bitcoin with the help of either NOK (Norwegian kroner), litecoin or ethereum. It has an open-end API for high volume traders that wish to act as market makers.<br />
<br />
==Informational links==<br />
<br />
[https://miraiex.com/no/fees Fees info] Information on fees for deposits, withdrawals and exchange.<br />
<br />
[https://developers.miraiex.com/ API documentation] API instructions for custom applications and how to connect with the exchange service.<br />
<br />
==Fees for trading==<br />
<br />
Miraiex charges a flat fee of 0,5% for both sale and buy orders. Users are granted a 5% cashback with each trade which is refunded at the end of the month.<br />
<br />
Bank deposits and withdrawals are free.<br />
<br />
==History and background==<br />
<br />
MiraiEx was conceptualized and founded in 2017, with the first beta version of the service going live in 2018. Founders include Øyvind Kvanes and Thuc Hoang.<br />
<br />
An integral part of its service is the ability to buy bitcoin and other cryptocurrencies with the help of "fast payments", in which transfers are credited within 60 minutes. <ref>[https://www.xn--privatkonomi-0jb.net/kryptovalutab%C3%B8rs/miraiex/ MiraiEx Vurdering - Privatøkonomen]</ref>.<br />
<br />
==External Links==<br />
<br />
* [https://miraiex.com/ MiraiEx.com] website<br />
<br />
==References==<br />
<references/><br />
<br />
[[Category:Exchanges]]<br />
[[Category:Services]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=CEX.IO&diff=68081CEX.IO2020-07-28T13:09:18Z<p>Furunodo: -eth</p>
<hr />
<div>{{infobox company|name=CEX.IO|image=[[File:CEX_Logo.png|225px]]<br />
|trading_name=CEX.IO<br />
|industry=[[Exchange|Bitcoin exchange]]<br />
|foundation=July, 2013<br />
|currencies=BTC, [[altcoin]]s, USD, EUR, RUB<br />
|website=https://cex.io<br />
}}<br />
<br />
==CEX.IO==<br />
<br />
'''CEX.IO''' is a UK-based Bitcoin crypto exchange developed out of the first ever [[cloud mining]] provider. <br />
<br />
==History==<br />
<br />
CEX.IO project development started in early 2013 and proceeded with launching the CEX.IO domain, acquiring assets of [[GHash.IO]] and, finally, registering a legal company CEX.IO LTD in November 2013. By this time, according to [[Blockchain.info]], GHash.IO has become the biggest mining pool, reaching over 42% of the overall Bitcoin mining power, which embodied the 51% attack threat. However, CEX.IO made an official statement, assuring the Bitcoin community that it would “take all necessary precautions to prevent reaching 51% of all hashing power, in order to maintain stability of the Bitcoin network.” In April 2014, CEX.IO user base exceeded 200,000 users. May 2014, CEX.IO imposed trade fee onto the exchange, lowered maintenance costs for cloud-based GHS and added IXC/BTC trading pair. On September 22, 2014, CEX.IO announced the successful launch of the first fiat currency — US dollars are accepted via bank transfer and payment cards. This upgrade allows users to trade Bitcoins and cloud-based hashing power (GHS) as well as deposit and withdraw funds at one place without using services of another exchange. On September 29, 2014, CEX.IO established the second fiat currency, the Euro, and implemented the possibility to deposit funds via [https://en.wikipedia.org/wiki/Single_Euro_Payments_Area SEPA]. <br />
January 12th, 2015, CEX.IO [http://www.coindesk.com/cex-io-halts-cloud-mining-service-due-low-bitcoin-price/ suspended] cloud mining services due to low Bitcoin price and high mining difficulty. Later on, CEX.IO has been developing as a trading platform. April 30th, 2015, the Bitcoin exchange has officially [http://www.coindesk.com/cex-io-opens-bitcoin-exchange-to-us/ entered] the USA market. <br />
CEX.IO has also obtained an MSB (Money Services Business) status in FinCEN, a bureau of the U.S. Department of the Treasury. As a registered MSB, CEX.IO has proved that the company complies with the Bank Secrecy Act requirements applicable to financial institutions as well as to each of the specific requirements applicable to MSBs. August 2015, CEX.IO added Russian Ruble as the third fiat currency. At the same time, the platform presented WebSocket API for professional traders. December 2015 is the release month of official CEX.IO Mobile Application. April 2016, CEX.IO launched [[altcoin]] trading. April 28th, 2016, CEX.IO launched withdrawals of USD, EUR, and RUB to payment cards (Visa/MasterCard). In October, 2016, GHash.IO pool was closed. October, 2016, CEX.IO launched variable trade fee schedule, and margin trading. In December, 2016, CEX.IO launched a new Bitcoin Affiliate Program.<br />
<br />
==Trading==<br />
<br />
CEX.IO exchange offers the following pairs to trade:<br />
<br />
*BTC/USD<br />
*BTC/EUR<br />
*BTC/GBP<br />
*BTC/RUB<br />
* [[altcoin]]s<br />
<br />
The exchange charges commission of 0% to 0.2% according to volume-based maker-taker [https://cex.io/fee-schedule fee schedule].<br />
<br />
CEX.IO offers [https://cex.io/margin-trading margin trading] for BTC/USD, BTC/EUR pairs with 1:2 and 1:3 leverages.<br />
<br />
==Fiat Currencies and Payment Methods==<br />
<br />
On CEX.IO, users are able to trade Bitcoin for such fiat currencies, as US Dollars, Euros, and Russian Ruble. CEX.IO claims to provide the best experience of buying Bitcoin with a payment card issued in any currency. The assertion is based on the exchange’s ideal conditions for quick and successful processing of card payments, the wide range of acceptable payment instruments, and numerous positive feedbacks from users.<br />
<br />
Deposit and withdrawal options:<br />
* Payment card (Visa/MasterCard)<br />
* Wire transfer<br />
* SEPA transfer<br />
<br />
==API==<br />
<br />
CEX.IO application programming interface (API) allows users to access and control their account using custom written software. Trade API is limited to 600 requests per 10 minutes.<br />
Apart from Trade API, CEX.IO offers WebSocket API with pusher technology, due to which users are able to subscribe to certain exchange updates. Such subscription allows getting real-time notifications about system changes without sending extra requests to get required information.<br />
<br />
==Security==<br />
<br />
Users can secure their accounts with passwords, but CEX.IO strongly recommends using Two-Factor Authentication (2FA).<br />
<br />
CEX.IO customers are free to use Google Authenticator<ref>[http://en.wikipedia.org/wiki/Google_Authenticator Google Authenticator on Wikipedia]</ref> or get a text or an audio message containing respective authorization code.<br />
<br />
CEX.IO is registered with the Information Commissioner’s Office (United Kingdom) as data processor and controller under registration reference ZA059396. The British ICO is an independent authority set up to uphold information rights in the public interest, promoting openness by public bodies and data privacy for individuals. Registration within ICO means CEX.IO complies with the European legislation on personal data privacy.<br />
<br />
CEX.IO possessed a Level 3 PCI DSS (PCI Data Security Standard) certificate. According to the latter, CEX.IO is compliant with the standards and is able to store, process or transmit cardholder data of users. All data is strongly encrypted. Apart from that, each photo submitted by a user during the verification process, is encrypted with a separated encryption key. <br />
<br />
==Cross-Platform Trading==<br />
<br />
CEX.IO offers cross-platform trading via website, mobile app, WebSocket and REST API, providing access to high liquidity orderbook for top currency pairs on the market. Mobile application is available for free download on [https://itunes.apple.com/app/cex.io/id1047225016 iOS] and [https://play.google.com/store/apps/details?id=io.cex.app.prod Android].<br />
<br />
==Affiliate Program==<br />
<br />
Within CEX.IO Affiliate Program, users get 30% of fee from all exchange transactions of their referred users. CEX.IO offers promotional tools, statistics and instant withdrawals of Affiliate Program rewards. <br />
<br />
==External links==<br />
<br />
*[http://cex.io CEX.IO website]<br />
*[http://ghash.io Ghash.IO website]<br />
*[https://www.facebook.com/pages/CEX.IO CEX.IO Facebook]<br />
*[https://twitter.com/cex_io CEX.IO Twitter]<br />
<br />
==References==<br />
<references /><br />
<br />
* [https://www.bitcoinmining.com/best-bitcoin-cloud-mining-contract-reviews/ Bitcoin Cloud Mining]<br />
<br />
[[Category:Exchanges]]<br />
[[Category:Mining_contractors]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Cryptofacilities&diff=68080Cryptofacilities2020-07-28T13:07:56Z<p>Furunodo: removed ", transparent and secure" as how can we even know this?</p>
<hr />
<div>'''Crypto Facilities''' offers individuals and institutions regulated trading 24/7/365. <br />
The firm is also the leading provider of cryptocurrency indices, calculating the CME CF Bitcoin Reference Rate and Real Time Index that power the CME Group’s Bitcoin Futures, and the CME CF Ether-Dollar Reference Rate and Ether-Dollar Real Time Index. <br />
Financial institutions, trading firms and data providers globally use Crypto Facilities’ indices and underlying data to optimise their cryptocurrency trading activity.<br />
<br />
Crypto Facilities Ltd is authorised and regulated by the Financial Conduct Authority (FRN 757895) and registered in England with registered number 9172128 and registered office at 25 Copthall Avenue, London EC2R 7BP, United Kingdom.<br />
<br />
<br />
==External links==<br />
*[http://www.cryptofacilities.com/trading?affiliate=d4b3ec00-55a7-4dbb-aebe-9aa34dca4043 CryptoFacilities website]<br />
<br />
==References==<br />
<references/><br />
<br />
[[Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Gatecoin&diff=68079Gatecoin2020-07-28T13:07:03Z<p>Furunodo: altcoins</p>
<hr />
<div>Gatecoin is an international financial institution for digital currencies. Available for the moment is an [[currency exchange|exchange]] for trading bitcoins, [[altcoins]] and several fiat currencies (USD, HKD, EUR).<br />
<br />
Gatecoin is Money-Service Operator licensed in Hong-Kong and incubated by the Hong-Kong Science Technology Parks (HKSTP) and Tsinghua University.<br />
<br />
<br />
==History==<br />
<br />
The online platform launched publicly in Q1 2015. Gatecoin is based in Hong Kong and operated by Gatecoin Ltd, incorporated on July 24th, 2013 in Hong Kong, SAR. Gatecoin won the 2014 Best Start-Up Prize for Central and East Asia at Talent Unleashed. Richard Branson and Steve Wozniak were part of the jury. Gatecoin co-founders are active members of the bitcoin community. Co-found and CEO Aurélien MENANT is one of the founding members of the Bitcoin Association of Hong Kong. Gatecoin regularly participates in conferences such as the Bitcoin Expo 2014 in Shanghai, the Inside Bitcoin conferences 2014 in Hong Kong, Paris 2014 and Singapore 2015.<br />
<br />
Gatecoin also created the website coincharities.org that works like Kickstarter that accepts donations in bitcoins.<br />
<br />
==Fees==<br />
<br />
Gatecoin offers 15 days of free trading for new users after making their first deposit. After that period, the fees depend on volumes and status:<br />
{| border="1" cellpadding="8" cellspacing="0"<br />
!Volume traded per month [BTC]<br />
!Fee* [%]<br />
|-<br />
|<20<br />
|0.35<br />
|-<br />
|<50<br />
|0.30<br />
|-<br />
|<100<br />
|0.25<br />
|-<br />
|<200<br />
|0.20<br />
|-<br />
|>200<br />
|0.15<br />
|-<br />
|}<br />
*Once you reach a threshold over a rolling 31 day period, the discounted fee is automatically applied to your following trades.<br />
<br />
{| border="1" cellpadding="8" cellspacing="0"<br />
!Account Type<br />
!Standard<br />
!Market Maker<br />
!Member<br />
|-<br />
|Minimal Trading Fees <br />
|0.15%<br />
|0.1%<br />
|0.05%<br />
|-<br />
|Account Pricing<br />
|Free<br />
|BTC 0.08/month<br />
|BTC 0.8/month<br />
|-<br />
|VIP Gateway<br />
|NO<br />
|YES<br />
|YES<br />
|-<br />
|VPN & FIX Access<br />
|NO<br />
|NO<br />
|YES<br />
|-<br />
|}<br />
For more detailed information, visit: https://gatecoin.com/public/feeschedule<br />
<br />
==See Also==<br />
<br />
* [[Buying bitcoins]]<br />
* [[Selling bitcoins]]<br />
<br />
==External Links==<br />
<br />
* [https://www.gatecoin.com Gatecoin.com] web site<br />
<br />
==References==<br />
<References /><br />
<br />
[[Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Mercado_Bitcoin&diff=68078Mercado Bitcoin2020-07-28T13:06:10Z<p>Furunodo: /* History */</p>
<hr />
<div>A market exchange where bitcoins can be bought and sold.<br />
<br />
The only currency traded for bitcoins by this service is BRL (Brazilian Real).<br />
<br />
==History==<br />
<br />
The service was announced in July 13, 2011<ref>[http://www.bitcoinbrasil.com.br/?p=177 The first Exchange in Brazil!]</ref>. The market did open to a limited trial later that month and opened registration to all on August 08, 2011<ref>[http://bitcointalk.org/index.php?topic=35623.0 Nova versão do Mercado Bitcoin no ar!]</ref><br />
<br />
On March 28, 2013 the service shut down citing losses from a security breach<ref>[http://bitcointalk.org/index.php?topic=160150.0 Problema do Mercado Bitcoin]</ref>.<br />
<br />
That same year, the service's founder partnered with entrepreneurs that finished reimbursing injured customers after the attack. They also invested in technology and security so that Mercado Bitcoin could get back on track. <ref>[https://www.istoedinheiro.com.br/noticias/mercado-digital/20150216/bitcoin-cai-real/232997.shtml O bitcoin cai na real]</ref><br />
<br />
Nowadays, Mercado Bitcoin trades Bitcoin and [[altcoin]]s.<br />
<br />
==See Also==<br />
<br />
* [[Selling bitcoins]]<br />
* [[Buying bitcoins]]<br />
<br />
==External Links==<br />
<br />
* [http://www.mercadobitcoin.com.br Mercado Bitcoin] website<br />
* [http://www.bitcoinbrasil.com.br Bitcoin Brasil] blog<br />
<br />
==References==<br />
<br />
<references /></div>Furunodohttps://en.bitcoin.it/w/index.php?title=TheRockTrading&diff=68077TheRockTrading2020-07-28T13:05:53Z<p>Furunodo: removing scamcoin</p>
<hr />
<div><br />
A [[currency exchange]] site serving those trading between bitcoins and the following currencies:<br />
<br />
* EURO<br />
* USD<br />
<br />
The service was launched June 07, 2011<ref>[https://therocktrading.com/news/315 Trade Bitcoin and Lindens!!]</ref>. Trading against Second Life Lindens is no longer available<ref>[https://www.therocktrading.com/en/news/583 New Second Life ToS]</ref>, due to change in Second Life ToS. Margin trading is also available.<br />
<br />
== Headquarter and Offices ==<br />
<br />
The Rock exchange is operated by The Rock Trading Ltd, which is a corporate entity <ref>[https://www.therocktrading.com/CertificateRegistration.pdf Certificate of Registration]</ref> registered in Malta, with its headquarters in Valletta. It has operational offices in Italy.<br />
<br />
== Deposits and Withdrawing ==<br />
<br />
Deposit methods available: SEPA transfers and OKPAY.<br />
<br />
It's the first Bitcoin exchange to have offered Bitcoin instant confirmations deposits, with multisig <ref>[https://www.therocktrading.com/en/news/bitcoin-instant-confirmation-implemented Bitcoin instant confirmations deposits]</ref>.<br />
<br />
==See Also==<br />
<br />
* [[Buying bitcoins]]<br />
* [[Selling bitcoins]]<br />
<br />
==External Links==<br />
<br />
* [https://therocktrading.com/ The Rock Currency Exchange] web site<br />
<br />
==References==<br />
<References /><br />
<br />
[[Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=CoinGate&diff=68076CoinGate2020-07-28T13:05:13Z<p>Furunodo: -scamcoin links</p>
<hr />
<div>{{infobox company|name=CoinGate|image=[[File:Coingate.png|256px]]<br />
|location=Vilnius, Lithuania<br />
|industry=[[:Category:Payment Processors | Payment Processor]]<br />
|founder=[[Jonas Gilys]] <br/>[[Dmitrijus Borisenka]] <br/> [[Irmantas Baciulis]]<br />
|twitter=CoinGatecom<br />
|facebook=coingatecom<br />
|website=https://coingate.com<br />
}}<br />
<br />
CoinGate was founded in 2014 and is incorporated in Vilnius, Lithuania. The company is a cryptocurrency payment gateway, enabling various businesses worldwide to accept Bitcoin. <br />
<br />
Currently serving over 4,500 business clients and 80,000 registered users, CoinGate offers payouts in Euros for a flat 1% fee, eliminating any risk associated with the price volatility of cryptocurrencies. Their merchants can also choose to keep the revenue in cryptocurrencies, providing numerous ways to make a withdrawal. <br />
<br />
Also, the company provides a platform for traders who wish to buy or sell their digital assets without making any deposits.<br />
<br />
Even though most CoinGate services are available in most parts of the world (See “Supported Countries” section), the company does not provide merchant services in the U.S.<br />
<br />
==Brief History==<br />
CoinGate went live in March 2015. The company started to gain attention by the end of February 2017 with the launch of the credit card option for buying Bitcoin. By May 2017, CoinGate processed its first 10,000 payments. <br />
<br />
Shortly after, in August, CoinGate went into a partnership with Shapeshift, adding over 50 additional cryptocurrencies to their provided payment options. In December 2017, the company also [https://blog.coingate.com/2017/12/coingate-implements-segwit-addresses/ integrated Segwit] addresses. By that time, the company had processed 100,000 payments in total.<br />
<br />
In 2018, CoinGate started growing rapidly. In February, [https://news.bitcoin.com/80000-new-merchants-in-europe-gains-option-to-accept-crypto/ CoinGate joined forces with e-commerce platform Prestashop], offering an easy solution for merchants to accept multiple cryptocurrencies using the official plugin.<br />
<br />
However, CoinGate is mostly known for pioneering the use-cases of the Lightning Network technology. In September 2018, CoinGate became one of the first payment processors in the world that [https://www.forbes.com/sites/billybambrough/2018/09/05/bitcoin-adoption-is-getting-a-massive-lightning-network-boost/#6d127321420c introduced Bitcoin Lightning Network payments] to thousands of online vendors. After CoinGate presented their developments at TechCrunch Disrupt event, the Verdict called CoinGate one of “[https://www.verdict.co.uk/techcrunch-disrupt-2018-startups/ future tech giants]”.<br />
<br />
CoinGate started 2019 strong, launching support for new native currencies each week. Since the year began, CoinGate natively integrated [[altcoin]]s.<br />
<br />
By January 2019, the payment gateway implemented ten cryptocurrencies natively. [https://blog.coingate.com/2019/01/year-review-milestones-future/ According to the article on CoinGate blog], CoinGate “processed close to 300,000 merchant payments since January (2018). In comparison, this is nearly three times more than last year”.<br />
<br />
==Merchant Tools==<br />
Merchants can receive Bitcoin and Altcoin payments via CoinGate using a [https://blog.coingate.com/2018/11/accept-bitcoin-payments-in-business-why-and-how/ range of tools]: plugins/modules for the most popular e-commerce systems, API, Point of Sale apps, and payment buttons. <br />
<br />
Additionally, customers can pay with over 50 Altcoins via Changelly integration, converting any payment to Bitcoin automatically. <br />
<br />
===Plugins===<br />
CoinGate offers a range of simple to use e-commerce integrations via [https://coingate.com/plugins/ plugins, modules or extensions] for accepting payments in Bitcoin and Altcoins.<br />
<br />
===API===<br />
[https://developer.coingate.com Application Programming Interface] allows businesses to integrate cryptocurrency payments into an online store with more customization. Using the CoinGate API, developers can create orders, get orders and list orders, as well as receive payment callbacks and order statuses. API integration is also possible using one of the CoinGate libraries: [https://github.com/coingate/coingate-php CoinGate PHP], [https://github.com/coingate/omnipay-coingate Omnipay], [https://rubygems.org/gems/coingate Ruby Gem]. A fully functional [https://sandbox.coingate.com Sandbox environment] is available for testing using Testnet Bitcoin.<br />
<br />
===Points of Sale===<br />
[https://coingate.com/pos Point of Sale] apps for Android and iOS allow businesses to accept Bitcoin payments on any [https://play.google.com/store/apps/details?id=com.coingate.pos&hl=en Android] or [https://itunes.apple.com/lt/app/bitcoin-pos/id1145472715 iOS] mobile device. Bitcoin Point of Sale web app, which can be accessed from any internet enabled device directly in a web browser, allows businesses to accept Bitcoin payments on any device with a web browser and an internet connection.<br />
<br />
===Payment Buttons===<br />
CoinGate [https://coingate.com/button Payment buttons] allow businesses to accept Bitcoin donations and other simple payments on any website. All three types of buttons - Fixed price, Slider and List - can be easily customized to include any necessary description, company logo, and cover image.<br />
<br />
==Settlement==<br />
<br />
Payments received from customers can be paid out in Euros to a bank account, AdvCash or Skrill wallet, avoiding the risk of price volatility. Alternatively, merchants can receive payouts in Bitcoin directly to their wallet. CoinGate charges a flat 1% fee for paid orders processed - there are no setup or subscription fees.<br />
<br />
==Trader Tools==<br />
<br />
===Buy Bitcoin and Altcoins===<br />
In addition to their services for merchants, CoinGate offers a platform for traders, allowing them to buy cryptocurrencies without making any deposits. After CoinGate receives the transfer, users can choose when to commit to their purchase (the maximum period is two weeks).<br />
<br />
A list of all available purchasing options:<br />
*SEPA Bank Transfer: Purchasing option for the Europe region. Allows purchasing most native cryptocurrencies listed on CoinGate. Registration and verified account are required;<br />
*Direct Bank Transfer: also available in China, Thailand, Indonesia, Malaysia, Vietnam. Allows purchasing most natively integrated cryptocurrencies listed on CoinGate. Registration and verified account are required;<br />
*[https://buy.coingate.com/ Credit and debit cards]: Instant payment option available worldwide. Allows purchasing most natively integrated cryptocurrencies listed on CoinGate. No registration required;<br />
*[https://coingate.com/buy-bitcoin-mobile Mobile balance] ([https://themerkle.com/coingate-lets-users-buy-bitcoin-with-their-mobile-credit/ phone credit]): Payment option available worldwide. Registration and verified account required;<br />
*[https://coingate.com/buy/skrill Skrill]: Instant payment option for Skrill users. No verification and registration are required as long as you are verified on Skrill.<br />
*[https://coingate.com/buy/neteller Neteller]: Instant payment option for Neteller users. No verification and registration are required as long as you are verified on Neteller.<br />
*QQPay: Payment option for the Asia region. Allows purchasing most natively integrated cryptocurrencies listed on CoinGate.<br />
<br />
For customers that use instant payment options, a quick KYC procedure is applied to ensure that both parties remain fully compliant with international laws.<br />
<br />
===Sell Bitcoin and Altcoins===<br />
Customers are also able to sell cryptocurrencies on CoinGate using numerous methods without the need to deposit funds first.<br />
The price of cryptocurrencies is locked before sending to CoinGate, guaranteeing users the amount of EUR they shall receive to their bank account, Skrill wallet or AdvCash platform.<br />
<br />
==Fees==<br />
<br />
===Merchant fees===<br />
For merchants, CoinGate charges 1% flat fee for payment processing. There are no setup or recurring fees, and no fees charged to shoppers. The service includes free SEPA transfers and Bitcoin payouts, as well as customer support & reporting dashboard.<br />
<br />
CoinGate also provides payment infrastructure for enterprise-grade projects and PSPs, meaning that particular clients may get a dedicated account manager, priority customer support and volume-based discounts.<br />
<br />
===Trader fees===<br />
CoinGate applies 3% buying and selling fee without depositing funds. Users can buy or sell directly to or from your wallet, also exchange fiat to crypto and vice versa. <br />
<br />
===Withdrawals===<br />
Euro withdrawals using SEPA bank transfer cost 0%. Still, customers might have to pay fees applied by a bank, depending on its services.<br />
<br />
Withdrawals to Bitcoin are free of charge. However, customers will have to pay the network’s transaction fee.<br />
<br />
Fee for Skrill and AdvCash withdrawals to Euros or U.S. Dollars is up to 1%. Customers will also have to pay a transaction fee.<br />
<br />
==Affiliate Program==<br />
CoinGate provides referral links that allow receiving 1% of the fees paid by traders who registered using your link. Referred customers will pay 0.5-1% lower fees than the usual 3%. Referrers will get a percentage of total payments that the referred customer makes.<br />
<br />
==Supported Countries==<br />
CoinGate provides a list of supported currencies [https://coingate.com/countries here].<br />
<br />
==Blog==<br />
All of the major CoinGate announcements are published on the official CoinGate blog. The blog also often features merchants, as well as shares the insights about the cryptocurrency industry. <br />
<br />
==Merchant List==<br />
CoinGate does not have an official merchant directory. However, the company often features their vendors on the official blog and social media channels. Here is a list of articles that feature CoinGate merchants:<br />
<br />
*[https://blog.coingate.com/2018/07/lightning-network-payments-launched-pilot/ We’ve Launched Lightning Network Payments for 100+ Merchants]<br />
*[https://blog.coingate.com/2019/02/support-libreoffice-software-crypto/ Support open source software LibreOffice with CoinGate]<br />
*[https://blog.coingate.com/2019/01/buy-video-games-bitcoin-altcoins/ Buy video games with Bitcoin (and altcoins) for PC and consoles]<br />
*[https://blog.coingate.com/2019/01/web-hosting-accept-bitcoin-crypto/ Web hosting services that accept Bitcoin and other cryptocurrencies]<br />
*[https://blog.coingate.com/2018/12/coingate-partners-with-sirin-labs-release-finney/ CoinGate partners with SIRIN LABS upon the release of FINNEY™]<br />
*[https://blog.coingate.com/2018/12/crypto-design-watches-chronoswiss/ Chronoswiss launches crypto-design watches]<br />
*[https://blog.coingate.com/2018/11/black-friday-bitcoin-promo/ Black Friday weekend promo: pay with crypto and win!]<br />
<br />
==Information For Press==<br />
CoinGate has a webpage with all the necessary information for media journalists, including the company’s logo, media contacts and trademark guidelines. You can find it [https://coingate.com/press here].<br />
<br />
==External Links==<br />
*[https://coingate.com CoinGate.com] website<br />
*[https://blog.coingate.com Official Blog]<br />
*[https://twitter.com/CoinGatecom Twitter]<br />
*[https://www.facebook.com/coingatecom/ Facebook]<br />
*[https://www.linkedin.com/company/coingate LinkedIn]<br />
*[https://www.instagram.com/coingatecom/ Instagram]<br />
*[https://developer.coingate.com CoinGate Developer API]<br />
*[http://bitcoinchaser.com/coingate Interview with CoinGate founder Dmitrijus Borisenka]<br />
<br />
==References==<br />
*[https://blog.coingate.com/2017/12/coingate-implements-segwit-addresses/ CoinGate implements SegWit addresses]<br />
*[https://news.bitcoin.com/80000-new-merchants-in-europe-gains-option-to-accept-crypto/ 80,000 New Merchants in Europe Gain Option to Accept Crypto]<br />
*[https://www.forbes.com/sites/billybambrough/2018/09/05/bitcoin-adoption-is-getting-a-massive-lightning-network-boost/#6d127321420c Bitcoin Adoption Is Getting A Massive Lightning Network Boost]<br />
*[https://www.verdict.co.uk/techcrunch-disrupt-2018-startups/ TechCrunch Disrupt 2018: Could these startups be the tech giants of the future?]<br />
*[https://blog.coingate.com/2019/01/year-review-milestones-future/ A year in review: achievements, milestones and the future]<br />
*[https://coingate.com/accept-altcoins A full list of accepted cryptocurrencies]<br />
*[https://blog.coingate.com/2018/11/accept-bitcoin-payments-in-business-why-and-how/ Accept Bitcoin payments in your business: why and how]<br />
*[https://coingate.com/plugins Payment plugins and modules for e-commerce platforms]<br />
*[https://developer.coingate.com CoinGate Application Programming Interface (API)]<br />
*[https://github.com/coingate/coingate-php CoinGate PHP GitHub]<br />
*[https://github.com/coingate/omnipay-coingate Omnipay GitHub]<br />
*[https://rubygems.org/gems/coingate Ruby Gem GitHub]<br />
*[https://sandbox.coingate.com Sandbox environment]<br />
*[https://coingate.com/pos Point of Sale]<br />
*[https://coingate.com/button Payment buttons]<br />
*[https://buy.coingate.com/ Buy cryptocurrencies with Credit Card without registration]<br />
*[https://coingate.com/buy-bitcoin-mobile Buy crypto with Phone Credit]<br />
*[https://themerkle.com/coingate-lets-users-buy-bitcoin-with-their-mobile-credit/ CoinGate Lets Users Buy Bitcoin With Their Mobile Credit]<br />
*[https://coingate.com/buy/skrill Buy cryptocurrencies with Skrill]<br />
*[https://coingate.com/buy/neteller Buy cryptocurrencies with Neteller]<br />
*[https://coingate.com/countries CoinGate supported countries]<br />
*[https://coingate.com/press Information for press]<br />
<br />
<br />
<br />
<br />
[[Category:Companies]]<br />
[[Category:Exchanges]]<br />
[[Category:Services]]<br />
[[Category:Shopping Cart Interfaces]]<br />
[[Category:Payment Processors]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Alfacash&diff=68075Alfacash2020-07-28T13:04:31Z<p>Furunodo: /* Supported currencies */ removing links to scamcoins</p>
<hr />
<div>== About the company ==<br />
<br />
[[File:468x60-1.png]]<br />
<br />
Founded in 2012, ALFAcashier is an easy-to-use exchange platform supporting all major electronic currencies, including Bitcoin, and erases the boundaries between electronic payment systems. <br />
<br />
The mission of the company is to provide a convenient and fast platform for electronic currency exchange, make money available in every country of the world and offer currency exchange services of ultimate quality. <br />
<br />
== History == <br />
<br />
ALFAcashier.com launched in 2012.<br />
<br />
Since 2014, ALFAcashier supports SEPA/SWIFT transfers to banks around the world, and secure storage of banking details and purse numbers of its members online.<br />
<br />
In September 2015, ALFAcashier made a major update of its website. The update introduces a number of useful features aimed at improving user experience and offering better, more convenient access to the site's services.<br />
<br />
==Supported currencies==<br />
<br />
Currencies: USD, USDT EUR, RUB, CNY, CAD, THB<br />
Electronic currencies and payment systems:<br />
* [https://www.alfacashier.com/buy/bitcoin Bitcoin (BTC)]<br />
* [https://www.alfacashier.com/buy/paxos Paxos Standard (PAX)]<br />
* [https://www.alfacashier.com/exchange/bitcoin/yandexmoney Yandex Money RUB]<br />
* [https://www.alfacashier.com/exchange/bitcoin/flexepin Flexepin CAD]<br />
* [https://buy.alfacashier.com/ Credit/debit cards (Visa/MasterCard USD, EUR)]<br />
* [https://www.alfacashier.com/exchange/sberbank/bitcoin Russian Banks RUB]<br />
<br />
==Fees and rates==<br />
<br />
The fees and exchange rates are changing and the best option is to check it on the site. <br />
<br />
Actual fees: [https://www.alfacashier.com/fees-and-limits www.alfacashier.com/fees-and-limits]<br /><br />
Actual exchange rate: [https://www.alfacashier.com/crypto-rates www.alfacashier.com/crypto-rates]<br />
<br />
==Cumulative discount program==<br />
<br />
Registered users are entitled to a progressive discount based on the total amount of funds exchanged through the service and applied to the service commission. <br /><br />
<br />
Service provides 4 account levels. The higher the client’s account level is, the more discount they will get. When the client's cumulative transaction amount reaches the required amount, their account will be upgraded to a high level automatically. In addition, in a future transaction, the client will get a discount of a new level.<br />
<br />
==Affiliate program up to 20% from commissions==<br />
<br />
ALFAcashier offers an easy and transparent referrer system for partners. Every registered user can participate in the [https://www.alfacashier.com/affiliate-program affiliate program]. Up to 20% from the service’s fee of referred exchange.<br />
<br />
==API==<br />
<br />
API allows to integrate exchange on website directly, so customers could exchange various currencies straight on your website without visiting [https://www.alfacashier.com/ ALFAcashier.com]!<br />
<br />
Right now API supports:<br />
<br />
* [https://www.alfacashier.com/developers#post_requests-create Order creation]<br />
<br />
* [https://www.alfacashier.com/developers#post_requests-rate Get order status]<br />
<br />
* [https://www.alfacashier.com/developers#post_requests-validateaddress Address validation]<br />
<br />
* [https://www.alfacashier.com/developers#get_requests-status Tracking your order status]<br />
<br />
* [https://www.alfacashier.com/developers#structures-country_codes Supported currency API list]<br />
<br />
And some more information about API you can find here [https://www.alfacashier.com/developers www.alfacashier.com/developers]<br />
<br />
==Limits and Restrictions==<br />
<br />
Please note that Bitcoin may take some time to confirm your payment. After it is confirmed, the exchange will be completed automatically. We do not accept registrations from individuals or companies based in the United States of the America. This includes US citizens residing overseas. If you fall under the above mentioned category or you are a US resident, please do not register an account with us or place any kind of exchange at all. We apologize for any inconvenience caused.<br/><br />
A full list of the rules and restrictions is available here: [https://www.alfacashier.com/legal www.alfacashier.com/legal]<br />
<br />
==External links==<br />
[https://www.alfacashier.com/ ALFAcashier exchanger]<br/><br />
[https://www.alfacashier.com/register User registration]<br/><br />
[https://www.alfacashier.com/news News]<br/><br />
[https://www.alfacashier.com/affiliate-program Affiliate Program] - You will be earn from 5% to 20% of the amount of any exchange operation performed by the user!<br/><br />
[https://www.alfacashier.com/discount Discount program]<br /><br />
[https://www.alfacashier.com/developers API]<br/><br />
[https://www.alfacashier.com/legal Legal]<br/><br />
[https://www.alfacashier.com/fees-and-limits Fees & Limits]<br/><br />
[https://www.alfacashier.com/crypto-rates Cryptocurrency rates]<br/><br />
[https://www.alfacashier.com/export-rates Export rates]<br/><br />
[https://www.alfacashier.com/vacancies Vacancies]<br/><br />
[https://www.alfacashier.com/support Contact customer support] - For quick and excellent support of your orders, we recommend that you apply directly to the site's ticket system.<br />
<br />
==References==<br />
<br />
<references /><br />
<br />
[[Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Talk:CoinField&diff=68074Talk:CoinField2020-07-28T13:02:00Z<p>Furunodo: </p>
<hr />
<div>This should probably go. [[User:Furunodo|Furunodo]] ([[User talk:Furunodo|talk]]) 14:28, 3 June 2020 (UTC)<br />
<br />
:Actually, replaced the whole thing with a link to a relevant thread on reddit. This seems more useful than deleting. Like this people can make up their own mind if they somehow bump on this page. [[User:Furunodo|Furunodo]] ([[User talk:Furunodo|talk]]) 13:01, 28 July 2020 (UTC)</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Talk:CoinField&diff=68073Talk:CoinField2020-07-28T13:01:22Z<p>Furunodo: :Actually, a link to relevant thread on reddit seems more useful than deleting. ~~~~</p>
<hr />
<div>This should probably go. [[User:Furunodo|Furunodo]] ([[User talk:Furunodo|talk]]) 14:28, 3 June 2020 (UTC)<br />
<br />
:Actually, a link to relevant thread on reddit seems more useful than deleting. [[User:Furunodo|Furunodo]] ([[User talk:Furunodo|talk]]) 13:01, 28 July 2020 (UTC)</div>Furunodohttps://en.bitcoin.it/w/index.php?title=File:Humaniq.jpg&diff=68072File:Humaniq.jpg2020-07-28T13:00:07Z<p>Furunodo: </p>
<hr />
<div>{{spam|Ethereum bla diagram}}<br />
<br />
== Licensing ==<br />
{{self|Cc-zero}}</div>Furunodohttps://en.bitcoin.it/w/index.php?title=CoinField&diff=68071CoinField2020-07-28T12:59:27Z<p>Furunodo: reddit: "Thanks for your reply. A few things just to mention here. While I cannot say for certain that this is a scam, there are certainly signs indicative of a scam. And in the world of cryptos, scammers are a dime a dozen. Exchanges need to prove</p>
<hr />
<div>{{infobox company|name=CoinField|image=<br />
|location=Tallinn, Estonia <br />
|industry= Bitcoin & Cryptocurrency Exchange<br />
|foundation=2018<br />
|founder= Bob Ras <br/> Reza Bashash <br/><br />
|twitter=<br />
|facebook=<br />
|website=https://www.coinfield.com/<br />
}}<br />
<br />
https://www.reddit.com/r/Bitcoin/comments/by2shk/potential_scam_coinfield/</div>Furunodohttps://en.bitcoin.it/w/index.php?title=CoinField&diff=68070CoinField2020-07-28T12:57:23Z<p>Furunodo: /* Sologenic */ Sologenic is altcoin scammy nonsense.</p>
<hr />
<div>{{infobox company|name=CoinField|image=<br />
|location=Tallinn, Estonia <br />
|industry= Bitcoin & Cryptocurrency Exchange<br />
|foundation=2018<br />
|founder= Bob Ras <br/> Reza Bashash <br/><br />
|twitter=<br />
|facebook=<br />
|website=https://www.coinfield.com/<br />
}}<br />
<br />
<br />
'''CoinField''' is a fully-regulated European-based [[Cryptocurrency]] exchange serving 193 countries worldwide.<ref>Jose Antonio Lanz,{{cite news | last = | first = | title= XRP Chosen As Base Pair For 130+ Coins By Canadian Exchange Coinfield | newspaper =| location = | pages = | language = | publisher =ethereumworldnews.com| date =23 March 2019 | url =https://ethereumworldnews.com/xrp-chosen-as-base-pair-for-130-coins-by-canadian-exchange-coinfield/ | accessdate =25 February 2020}}</ref> The exchange offers the trade of 21 cryptocurrencies.<ref>{{cite news | last = | first = | title= Canada's CoinField Exchange Set To Launch Ripple And Stellar Trading Pair (XLM/XRP) | newspaper =| location = | pages = | language = | publisher =bitcoinexchangeguide.com| date =14 December 2018 | url =https://bitcoinexchangeguide.com/canadas-coinfield-exchange-set-to-launch-ripple-and-stellar-trading-pair-xlm-xrp/ | accessdate =25 February 2020}}</ref> It currently has more than 200,000 users and a daily trading volume of $30m USD.<ref>{{cite news | last = | first = | title= Crypto Exchange CoinField Unveils Secret XRP Project, Plans to Tokenize Stocks and ETFs | newspaper =| location = | pages = | language = | publisher =dailyhodl.com| date =15 October 2019 | url =https://dailyhodl.com/2019/10/15/crypto-exchange-coinfield-unveils-secret-xrp-project-plans-to-tokenize-stocks-and-etfs/ | accessdate =25 February 2020}}</ref><br />
<br />
==History and Founders==<br />
[https://www.coinfield.com/ CoinField] was founded in April 2018 by Bob Ras, who is the current CEO of the company, and Reza Bashash, who is the CTO.<ref>Solomon Odunayo,{{cite news | last = | first = | title=XRP is Better than Ethereum – CoinField CEO, Bob Ras| newspaper =| location = | pages = | language = | publisher =techbullion.com| date =23 November 2019| url =https://newslogical.com/xrp-is-better-than-ethereum-coinfield-ceo-bob-ras/ | accessdate =25 February 2020}}</ref><ref name="NEWS">Khalid Lawal,{{cite news | last = | first = | title= SOLO & XRP Wallet Apps to Go Live on Apple Store & Google Play | newspaper =| location = | pages = | language = | publisher =newslogical.com| date =3 February 2020 | url =https://newslogical.com/solo-xrp-wallet-apps-to-go-live-on-apple-store-google-play/ | accessdate =25 February 2020}}</ref> Before the launching of CoinField, Bob had several successful ventures in manufacturing, marketing, and technology industries while Reza, an engineer and founder of several tech companies, has experience working in Artificial Intelligence and FinTech industries for more than ten years.<ref>Adrian Barkley,{{cite news | last = | first = | title=Ripple’s IPO Will Make The Firm Stronger According To The Sologenic CEO| newspaper =| location = | pages = | language = | publisher =cryptodaily.co.uk| date =20 February 2020| url =https://cryptodaily.co.uk/2020/02/ripple-ipo-firm-strong-ceo | accessdate =25 February 2020}}</ref><br />
<br />
The CoinField Head Office is currently located in Tallinn, Estonia. The company employs 35+ people with a variety of skill sets.<ref name="NEWS"/><br />
<br />
===Regulations and licences===<br />
CoinField is fully regulated and compliant in 193 countries worldwide.<ref>Benjamin Pirus,{{cite news | last = | first = | title=Chainalysis to Monitor AML Compliance for Crypto Exchange CoinField| newspaper =| location = | pages = | language = | publisher =cointelegraph.com| date =21 February 2020 | url =https://cointelegraph.com/news/chainalysis-to-monitor-aml-compliance-for-crypto-exchange-coinfield | accessdate =25 February 2020}}</ref> There are 39 countries where CoinField does not offer service due to regulations.<ref>Anthonia Isichei ,{{cite news | last = | first = | title=CoinField Integrates Chainalysis KYT Surveillance Tool to Fight Money Laundering| newspaper =| location = | pages = | language = | publisher =btcmanager.com| date =21 February 2020 | url =https://btcmanager.com/coinfield-chainalysis-kyt-surveillance-tool-money-laundering/?q=/coinfield-chainalysis-kyt-surveillance-tool-money-laundering/&q=/coinfield-chainalysis-kyt-surveillance-tool-money-laundering/ | accessdate =25 February 2020}}</ref> CoinField does not currently operate in the United States but aims to start trading there soon.<br />
<br />
In February 2020, CoinField partnered with [[blockchain]] analysis company ''Chainalysis''.<ref>Ali Raza,{{cite news | last = | first = | title= CoinField Partners With Chainalysis To Leverage KYT and AML Features| newspaper =| location = | pages = | language = | publisher =insidebitcoins.com| date =21 February 2020 | url =https://insidebitcoins.com/news/coinfield-partners-with-chainalysis-to-leverage-kyt-and-aml-features/251561 | accessdate =25 February 2020}}</ref><ref>Lili Chuang,{{cite news | last = | first = | title= Chainalysis Teams Up With Coinfield to Provide Crypto Compliance Solution| newspaper =| location = | pages = | language = | publisher =coinnewsspan.com| date = | url =https://www.coinnewsspan.com/chainalysis-teams-up-with-coinfield-to-provide-crypto-compliance-solution/ | accessdate =25 February 2020}}</ref><ref>{{cite news | last = | first = | title= Chainalysis to Monitor AML Compliance for Crypto Exchange CoinField| newspaper =| location = | pages = | language = | publisher =thebulletintime.com| date =23 February 2020 | url =https://www.thebulletintime.com/news/chainalysis-to-monitor-aml-compliance-for-crypto-exchange-coinfield/ | accessdate =25 February 2020}}</ref> The partnership allows CoinField to access the company’s Know-Your-Transaction (KYT) software, to prevent money laundering and to identify high-risk cryptocurrency transactions in real-time.<ref>{{cite news | last =Emilio | first =Janus | title= Chainalysis Enables Coinfield Exchange To ‘Know Your Transaction’ | newspaper =| location = | pages = | language = | publisher =bitcoinist.com| date =21 February 2020 | url =https://bitcoinist.com/chainalysis-enables-coinfield-exchange-to-know-your-transaction/ | accessdate =25 February 2020}}</ref><ref>{{cite news | last = | first = | title= CoinField Partners With Chainalysis To Leverage KYT and AML Features| newspaper =| location = | pages = | language = | publisher =elevenews.com| date = | url =https://elevenews.com/2020/02/21/coinfield-partners-with-chainalysis-to-leverage-kyt-and-aml-features/ | accessdate =25 February 2020}}</ref><ref>Arnab Shome,{{cite news | last = | first = | title= CoinField Taps Chainalysis’ KYT for Real-Time Crypto Monitoring| newspaper =| location = | pages = | language = | publisher =financemagnates.com| date =21 February 2020 | url =https://www.financemagnates.com/cryptocurrency/news/coinfield-taps-chainalysis-kyt-for-real-time-crypto-monitoring/ | accessdate =25 February 2020}}</ref><ref>Johnson Go,{{cite news | last = | first = | title=Coinfield and Chainalysis for crypto monitoring| newspaper =| location = | pages = | language = | publisher =cryptopolitan.com| date =22 February 2020 | url =https://www.cryptopolitan.com/coinfield-and-chainalysis-crypto-monitoring/ | accessdate =25 February 2020}}</ref><br />
<br />
==Fiats== <br />
There are currently six fiat currency deposit and withdrawal options for CoinField customers. These are USD, EUR, CAD, GBP, AED and JPY.<ref>Chayanika Deka,{{cite news | last =Emilio | first =Janus | title= CoinField becomes Ripple’s verified validator; hints at upcoming XRPL project | newspaper =| location = | pages = | language = | publisher =eng.ambcrypto.com| date =11 October 2019 | url =https://eng.ambcrypto.com/coinfield-becomes-ripples-verified-validator-hints-at-upcoming-xrpl-project/ | accessdate =25 February 2020}}</ref><br />
<br />
===Cryptocurrencies===<br />
FIAT currencies can be traded on CoinField’s platform for 21 cryptocurrencies including Bitcoin (BTC), Bitcoin Cash (BCH) Bitcoin Gold (BTG) Ethereum (ETH), Litecoin (LTC), XRP, USDT, USD Coin (USDC), ZEC (Zcash), Digibyte (DGB) Ox (ZRX) XLM, Golem (GNT), Auger (REP), OmiseGo (OMG), TRX, SALT, Zilliqa (ZIL), Civic (CVC), LOOM, BAT, DASH and SOLO.<ref>Adriana Hamacher,{{cite news | last = | first = | title= Coinfield to open up 30,000 stocks for crypto trading on Ripple's XRPL| newspaper =| location = | pages = | language = | publisher =finance.yahoo.com| date =15 October 2020 | url =https://finance.yahoo.com/news/coinfield-open-30-000-stocks-124720163.html?.tsrc=rss | accessdate =25 February 2020}}</ref><ref>Alex Dovbnya,{{cite news | last = | first = | title= 130+ XRP Pairs Being Added to Canada’s Coinfield Exchange| newspaper =| location = | pages = | language = | publisher =u.today| date =11 October 2019 | url =https://u.today/130-xrp-pairs-being-added-to-canadas-coinfield-exchange | accessdate =25 February 2020}}</ref><br />
<br />
==Products==<br />
===Centralized Exchange===<br />
The CoinField centralized exchange platform is hosted by CoinField's isolated servers and utilizes multi-signature cold storage wallets.<ref>Biraajmaan Tamuly,{{cite news | last = | first = | title= XRPTipBot links up with Canada’s CoinField to bolster XRP token adoption| newspaper =| location = | pages = | language = | publisher =eng.ambcrypto.com| date =25 July 2019 | url =https://eng.ambcrypto.com/xrptipbot-links-up-with-canadas-coinfield-to-bolster-xrp-token-adoption/ | accessdate =25 February 2020}}</ref>The exchange infrastructure is consistently audited by third parties to ensure compliance with the cybersecurity standards.<ref>{{cite news | last = | first = | title= XRP is on Fire as CoinField Mulls the Possibility of Using it as a Base Currency| newspaper =| location = | pages = | language = | publisher =cryptovest.com| date =26 September 2018 | url =https://cryptovest.com/news/xrp-is-on-fire-as-coinfield-mulls-the-possibility-of-using-it-as-a-base-currency/ | accessdate =25 February 2020}}</ref><br />
<br />
===Wallet and App===<br />
CoinField operates a wallet management system to enable users to quickly and securely interact with their assets on the blockchain.<ref name="Daily">{{cite news | last = | first = | title= Mysterious ‘Game Changing’ XRP Project Underway, Says Crypto Exchange CoinField | newspaper =| location = | pages = | language = | publisher =dailyhodl.com| date =12 September 2019 | url =https://dailyhodl.com/2019/09/12/mysterious-game-changing-xrp-project-underway-says-crypto-exchange-coinfield/ | accessdate =25 February 2020}}</ref> CoinField’s mobile app allows users to evaluate charts on multiple time frames to facilitate informed crypto trading decisions. <ref>{{cite news | last = | first = | title= CoinField announces an incentive program for Open Source Developers within Sologeni| newspaper =| location = | pages = | language = | publisher =globenewswire.com| date =4 December 2019 | url =https://www.globenewswire.com/news-release/2019/12/04/1956137/0/en/CoinField-announces-an-incentive-program-for-Open-Source-Developers-within-Sologenic.html | accessdate =25 February 2020}}</ref><br />
<br />
Wallets are directly synchronized to the blockchain and hosted securely on private isolated servers to ensure secure transactions.The app is available on both the App Store and Google Play.<ref name="Daily"/><br />
<br />
===OTC Trading Desk===<br />
CoinField’s Institutional Account & Over the Counter (OTC) Trading Desk enhances the execution of larger trades for corporate and high-net-worth individuals by offering more substantial liquidity, fast settlements, and privacy for each trade.<ref>Adrian Zmudzinski,{{cite news | last = | first = | title= Crypto Exchange CoinField Launches XRP Validator, Teases New Ecosystem| newspaper =| location = | pages = | language = | publisher =cointelegraph.com| date =7 October 2019| url =https://cointelegraph.com/news/crypto-exchange-coinfield-launches-xrp-validator-teases-new-ecosystem | accessdate =25 February 2020}}</ref> There are no trading fees, and clients get a dedicated account manager.<ref>Carlos Terenzi,{{cite news | last = | first = | title= What’s CoinField XRP Project All About?| newspaper =| location = | pages = | language = | publisher =usethebitcoin.com| date =| url =https://usethebitcoin.com/whats-coinfield-xrp-project-all-about/ | accessdate =25 February 2020}}</ref> CoinField is in the process of extending its OTC services to 24 hours a day.<ref>Jimmy Aki,{{cite news | last = | first = | title= Canadian Platform to Become the Major Global Crypto Exchange by Expanding to 100 Countries| newspaper =| location = | pages = | language = | publisher =cointelegraph.com| date =15 January 2019| url =https://cointelegraph.com/news/canadian-platform-to-become-the-major-global-crypto-exchange-by-expanding-to-100-countries | accessdate =25 February 2020}}</ref><br />
<br />
===White Label===<br />
CoinField offers a white label package for customers looking to start their exchange using CoinField’s software. CoinField’s centralized exchange has a team of 35+ experts with extensive experience ranging from blockchain to high-frequency trading software implementation.<ref name="CRD">Samantha Hurst,{{cite news | last = | first = | title= Canada’s CoinField Debuts White Label Crypto Exchange Software Licensing Program| newspaper =| location = | pages = | language = | publisher =crowdfundinsider.com| date =20 February 2019| url =https://www.crowdfundinsider.com/2019/02/144717-canadas-coinfield-debuts-white-label-crypto-exchange-software-licensing-program/ | accessdate =25 February 2020}}</ref><br />
<br />
The white-label exchange package includes access to CoinField’s deep liquidity pool to satisfy demand during the high peaks of trading activity, as well as 200+ digital assets, military-grade security systems, market pairing against fiat currencies, and more.<ref name="CRD"/><br />
<br />
===Sologenic=== <br />
<br />
Sologenic is altcoin scammy nonsense.<br />
<br />
==Franchising== <br />
CoinField offers entrepreneurs the opportunity to franchise CoinField’s brand. Franchise customers can start a CoinField franchise in their own country and have access to CoinField’s services, portfolio of coins, and profit-sharing.<ref>{{cite news | last = | first = | title= CoinField Introduces Crypto Exchange Franchises in 15 Markets| newspaper =| location = | pages = | language = | publisher =globalfintechseries.com| date =23 January 2020 | url =https://globalfintechseries.com/coinfield-introduces-crypto-exchange-franchises-in-15-markets/ | accessdate =25 February 2020}}</ref><br />
<br />
Currently, franchise opportunities are available in Argentina, Australia, Bahrain, Brazil, France, Japan, Malaysia, Mexico, New Zealand, Qatar, Russia, Saudi Arabia, Singapore, South Korea, UAE, United Kingdom, and the USA.<ref>{{cite news | last = | first = | title= CoinField Introduces Crypto Exchange Franchises in 15 Markets| newspaper =| location = | pages = | language = | publisher =globalfintechseries.com| date =23 January 2020 | url =https://globalfintechseries.com/coinfield-introduces-crypto-exchange-franchises-in-15-markets/ | accessdate =25 February 2020}}</ref><br />
<br />
==See also==<br />
* [[Sologenic]]<br />
<br />
==External Links==<br />
* [https://www.sologenic.com/ Sologenic website]<br />
<br />
==References==<br />
<br />
[[Category:Exchanges]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Timestamp&diff=68057Timestamp2020-07-13T10:09:22Z<p>Furunodo: Redirected page to Block timestamp</p>
<hr />
<div>#redirect [[Block timestamp]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Block_timestamp&diff=68056Block timestamp2020-07-13T10:06:11Z<p>Furunodo: </p>
<hr />
<div>Each block contains a [http://en.wikipedia.org/wiki/Unix_time Unix time] timestamp. In addition to serving as a source of variation for the [[Block_hashing_algorithm|block hash]], they also make it more difficult for an adversary to manipulate the [[block chain]].<br />
<br />
A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours. "Network-adjusted time" is the median of the timestamps returned by all nodes connected to you. As a result block timestamps are not exactly accurate, and they do not need to be. Block times are accurate only to within an hour or two.<br />
<br />
Whenever a node connects to another node, it gets a UTC timestamp from it, and stores its offset from node-local UTC. The network-adjusted time is then the node-local UTC plus the median offset from all connected nodes. Network time is never adjusted more than 70 minutes from local system time, however.<br />
<br />
Bitcoin uses an unsigned integer for the timestamp, so the [[:Wikipedia:Year_2038_problem|year 2038 problem]] is delayed for another 68 years.<br />
<br />
See also [[epoch]], [[genesis block]].<br />
<br />
[[Category:Technical]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Epoch&diff=68055Epoch2020-07-13T10:05:50Z<p>Furunodo: </p>
<hr />
<div>With a Bitcoin '''epoch''' people usually mean a period of roughly 4 years with a specific mining reward. The first epoch started with the [[genesis block]] in 2009, and a block reward of 50 BTC.<br />
<br />
From May 2020 until some time in 2024, we're in the 4th mining epoch. Block rewards in this epoch are 6.25 BTC.<br />
<br />
See also [[Block timestamp]]<br />
<br />
{{stub}}<br />
<br />
[[Category:Technical]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Block_timestamp&diff=68054Block timestamp2020-07-13T10:05:14Z<p>Furunodo: </p>
<hr />
<div>Each block contains a [http://en.wikipedia.org/wiki/Unix_time Unix time] timestamp. In addition to serving as a source of variation for the [[Block_hashing_algorithm|block hash]], they also make it more difficult for an adversary to manipulate the block chain.<br />
<br />
A timestamp is accepted as valid if it is greater than the median timestamp of previous 11 blocks, and less than the network-adjusted time + 2 hours. "Network-adjusted time" is the median of the timestamps returned by all nodes connected to you. As a result block timestamps are not exactly accurate, and they do not need to be. Block times are accurate only to within an hour or two.<br />
<br />
Whenever a node connects to another node, it gets a UTC timestamp from it, and stores its offset from node-local UTC. The network-adjusted time is then the node-local UTC plus the median offset from all connected nodes. Network time is never adjusted more than 70 minutes from local system time, however.<br />
<br />
Bitcoin uses an unsigned integer for the timestamp, so the [[:Wikipedia:Year_2038_problem|year 2038 problem]] is delayed for another 68 years.<br />
<br />
See also [[epoch]], [[genesis block]].<br />
<br />
[[Category:Technical]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Genesis_block&diff=68053Genesis block2020-07-13T10:04:48Z<p>Furunodo: /* Timestamp */</p>
<hr />
<div>A '''genesis block''' is the first block of a [[block chain]]. Modern versions of Bitcoin number it as '''block 0''', though very early versions counted it as block 1. The genesis block is almost always hardcoded into the software of the applications that utilize its block chain. It is a special case in that it does not reference a previous block, and for [[Bitcoin]] and almost all of its derivatives, it produces an unspendable subsidy.<br />
<br />
== Main network genesis block ==<br />
Here is a representation of the genesis block<ref name="block">{{cite block|hash=000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f|0|year=2009|month=01|day=03}}</ref> as it appeared in a comment in an old version of Bitcoin ([http://sourceforge.net/p/bitcoin/code/133/tree/trunk/main.cpp#l1613 line 1613]). The first section defines exactly all of the variables necessary to recreate the block. The second section is the block in standard printblock format, which contains shortened versions of the data in the first section.<br />
<br />
GetHash() = 0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f<br />
hashMerkleRoot = 0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b<br />
txNew.vin[0].scriptSig = 486604799 4 0x736B6E616220726F662074756F6C69616220646E6F63657320666F206B6E697262206E6F20726F6C6C65636E61684320393030322F6E614A2F33302073656D695420656854<br />
txNew.vout[0].nValue = 5000000000<br />
txNew.vout[0].scriptPubKey = 0x5F1DF16B2B704C8A578D0BBAF74D385CDE12C11EE50455F3C438EF4C3FBCF649B6DE611FEAE06279A60939E028A8D65C10B73071A6F16719274855FEB0FD8A6704 OP_CHECKSIG<br />
block.nVersion = 1<br />
block.nTime = 1231006505<br />
block.nBits = 0x1d00ffff<br />
block.nNonce = 2083236893<br />
<br />
CBlock(hash=000000000019d6, ver=1, hashPrevBlock=00000000000000, hashMerkleRoot=4a5e1e, nTime=1231006505, nBits=1d00ffff, nNonce=2083236893, vtx=1)<br />
CTransaction(hash=4a5e1e, ver=1, vin.size=1, vout.size=1, nLockTime=0)<br />
CTxIn(COutPoint(000000, -1), coinbase 04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73)<br />
CTxOut(nValue=50.00000000, scriptPubKey=0x5F1DF16B2B704C8A578D0B)<br />
vMerkleTree: 4a5e1e<br />
===Hash===<br />
The hash of the genesis block, '''000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f''',<ref name="block"/> has two more leading hex zeroes than were required for an early block.<br />
<br />
===Coinbase===<br />
[[File:jonny1000thetimes.png|thumb|256px|The Times 03/Jan/2009]]<br />
The [[coinbase]] parameter (seen above in hex) contains, along with the normal data, the following text:<ref>[http://web.archive.org/web/20140309004338/http://uk.reuters.com/article/2009/01/03/idUKPTIP32510920090103 Reuters' reference on The Financial Times article (archive.org cached copy)]</ref><br />
<br />
<blockquote>The Times 03/Jan/2009 Chancellor on brink of second bailout for banks<ref name="block"/></blockquote><br />
<br />
This was probably intended as proof that the block was created on or after January 3, 2009, as well as a comment on the instability caused by fractional-reserve banking. Additionally, it suggests that [[Satoshi Nakamoto]] may have lived in the United Kingdom.<ref>{{cite web|author=Davis, J.|year=2011|title=The Crypto-Currency|publisher=''The New Yorker''|url=http://www.newyorker.com/magazine/2011/10/10/the-crypto-currency}}</ref><br />
<br />
<br />
This detail, "second bailout for banks" could also suggest that the fact a supposedly liberal and capitalist system, rescuing banks like that, was a problem for satoshi . . . the choosen topic could have a meaning about bitcoin s purpose . . .<br />
<br />
===Block reward===<br />
The first 50 BTC block reward went to [[address]] ''1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa'',<ref name="block"/> though this reward can't be spent due to a quirk in the way that the genesis block is expressed in the code. It is not known if this was done intentionally or accidentally.<ref>http://bitcoin.stackexchange.com/questions/10009/why-can-t-the-genesis-block-coinbase-be-spent</ref><ref>https://www.reddit.com/r/Bitcoin/comments/1nc13r/the_first_50btc_block_reward_cant_be_spend_why/</ref><ref>https://github.com/bitcoin/bitcoin/blob/9546a977d354b2ec6cd8455538e68fe4ba343a44/src/main.cpp#L1668 - Genesis block transaction treated as a special case in the reference code</ref> It is believed that other outputs sent to this address are spendable, but it is unknown if Satoshi Nakamoto has the private key for this particular address, if one existed at all.<br />
<br />
===Timestamp===<br />
Although the average time between Bitcoin blocks is 10 minutes, the [[block timestamp|timestamp]] of the next block is a full 6 days after the genesis block. One interpretation is that Satoshi was working on bitcoin for some time beforehand and the ''The Times'' front page prompted him to release it to the public. He then mined the genesis block with a timestamp in the past to match the headline. It is also possible that, since the block's hash is so low, he may have spent 6 days mining it with the same timestamp before proceeding to block 1. The [[prenet hypothesis]] suggests that the genesis block was solved on January 3, but the software was tested by Satoshi Nakamoto using that genesis block until January 9, when all the test blocks were deleted and the genesis block was reused for the main network.<br />
<br />
===Raw block data===<br />
<br />
The [https://bitcointalk.org/index.php?topic=52706 raw hex version] of the Genesis block looks like:<br />
00000000 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br />
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br />
00000020 00 00 00 00 3B A3 ED FD 7A 7B 12 B2 7A C7 2C 3E ....;£íýz{.²zÇ,><br />
00000030 67 76 8F 61 7F C8 1B C3 88 8A 51 32 3A 9F B8 AA gv.a.È.ÈŠQ2:Ÿ¸ª<br />
00000040 4B 1E 5E 4A 29 AB 5F 49 FF FF 00 1D 1D AC 2B 7C K.^J)«_Iÿÿ...¬+|<br />
00000050 01 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 ................<br />
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................<br />
00000070 00 00 00 00 00 00 FF FF FF FF 4D 04 FF FF 00 1D ......ÿÿÿÿM.ÿÿ..<br />
00000080 01 04 45 54 68 65 20 54 69 6D 65 73 20 30 33 2F ..EThe Times 03/<br />
00000090 4A 61 6E 2F 32 30 30 39 20 43 68 61 6E 63 65 6C Jan/2009 Chancel<br />
000000A0 6C 6F 72 20 6F 6E 20 62 72 69 6E 6B 20 6F 66 20 lor on brink of <br />
000000B0 73 65 63 6F 6E 64 20 62 61 69 6C 6F 75 74 20 66 second bailout f<br />
000000C0 6F 72 20 62 61 6E 6B 73 FF FF FF FF 01 00 F2 05 or banksÿÿÿÿ..ò.<br />
000000D0 2A 01 00 00 00 43 41 04 67 8A FD B0 FE 55 48 27 *....CA.gŠý°þUH'<br />
000000E0 19 67 F1 A6 71 30 B7 10 5C D6 A8 28 E0 39 09 A6 .gñ¦q0·.\Ö¨(à9.¦<br />
000000F0 79 62 E0 EA 1F 61 DE B6 49 F6 BC 3F 4C EF 38 C4 ybàê.aÞ¶Iö¼?Lï8Ä<br />
00000100 F3 55 04 E5 1E C1 12 DE 5C 38 4D F7 BA 0B 8D 57 óU.å.Á.Þ\8M÷º..W<br />
00000110 8A 4C 70 2B 6B F1 1D 5F AC 00 00 00 00 ŠLp+kñ._¬....<br />
<br />
Broken down it looks like this:<br />
<br />
01000000 - version<br />
0000000000000000000000000000000000000000000000000000000000000000 - prev block<br />
3BA3EDFD7A7B12B27AC72C3E67768F617FC81BC3888A51323A9FB8AA4B1E5E4A - merkle root<br />
29AB5F49 - timestamp<br />
FFFF001D - bits<br />
1DAC2B7C - nonce<br />
01 - number of transactions<br />
01000000 - version<br />
01 - input<br />
0000000000000000000000000000000000000000000000000000000000000000FFFFFFFF - prev output<br />
4D - script length<br />
04FFFF001D0104455468652054696D65732030332F4A616E2F32303039204368616E63656C6C6F72206F6E206272696E6B206F66207365636F6E64206261696C6F757420666F722062616E6B73 - scriptsig<br />
FFFFFFFF - sequence<br />
01 - outputs<br />
00F2052A01000000 - 50 BTC<br />
43 - pk_script length<br />
4104678AFDB0FE5548271967F1A67130B7105CD6A828E03909A67962E0EA1F61DEB649F6BC3F4CEF38C4F35504E51EC112DE5C384DF7BA0B8D578A4C702B6BF11D5FAC - pk_script<br />
00000000 - lock time<br />
==References==<br />
<references/><br />
<br />
[[zh-cn:创世block]]<br />
[[es:Bloque Génesis]]<br />
__NOTOC__<br />
<br />
[[Category:Technical]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Epoch&diff=68052Epoch2020-07-13T10:03:10Z<p>Furunodo: stub</p>
<hr />
<div>With a Bitcoin '''epoch''' people usually mean a period of roughly 4 years with a specific mining reward. From May 2020 until some time in 2024, we're in the 4th mining epoch. Block rewards in this epoch are 6.25 BTC.<br />
<br />
See also [[Block timestamp]]<br />
<br />
{{stub}}<br />
<br />
[[Category:Technical]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Talk:Bech32_adoption&diff=68046Talk:Bech32 adoption2020-07-02T09:32:26Z<p>Furunodo: I don't think we need "Other Services: Casinos, marketplaces, etc that let users withdraw money" here. It just attracts businesses that will want to add their link here. This doesn't add value to the wiki. ~~~~</p>
<hr />
<div>I don't think we need "Other Services: Casinos, marketplaces, etc that let users withdraw money" here. It just attracts businesses that will want to add their link here. This doesn't add value to the wiki. [[User:Furunodo|Furunodo]] ([[User talk:Furunodo|talk]]) 09:32, 2 July 2020 (UTC)</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Bech32_adoption&diff=68045Bech32 adoption2020-07-02T09:31:24Z<p>Furunodo: /* Other Services */ commenting this out, see talk page</p>
<hr />
<div>[[Bech32]] is a new bitcoin [[address]] format specified by [[BIP 0173]]. This page tracks the adoption of [[Bech32]].<br />
<br />
Ideally wallets and services would first support ''sending to'' bech32 addresses. After almost everything can send to, then people may be willing to adopt bech32 widely for receiving.<br />
<br />
The amount of bech32 addresses on the blockchain is tracked on this website: https://p2sh.info/dashboard/db/bech32-statistics?orgId=1<br />
<br />
{| class="wikitable"<br />
|-<br />
| {{No}} ||<br />
|-<br />
| {{Evaluating|??}} || Maybe / Haven't checked / placeholder<br />
|-<br />
| {{Planned}} || The developers said they plan to<br />
|-<br />
| {{Acceptable|PR Merged}} || In the case of software, code has been written and merged, and it will be in next release.<br />
|-<br />
| {{Yes}} || Feature has been released<br />
|}<br />
<br />
=== Software Wallets ===<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Send to !! Create/receive !! Notes<br />
|-<br />
| Bitcoin Core || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Bitcoin Knots || {{Yes}} || {{Yes}} ||<br />
|-<br />
| bcoin || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Armory || {{Yes}} || {{No}} ||<br />
|-<br />
| JoinMarket || {{Yes}} || {{No}} ||<br />
|-<br />
| GreenAddress || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Breadwallet || {{Yes}} || {{No}} || https://twitter.com/udiWertheimer/status/975810157941796864<br />
|-<br />
| Samourai Wallet || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Coinomi || {{Yes}} || {{Yes}} || [https://www.reddit.com/r/Bitcoin/comments/865qn1/coinomi_wallet_beta_has_segwit_support/ reddit source]<br />
|-<br />
| BTC.com || {{Yes}} || {{No}} ||<br />
|-<br />
| Casa || {{Yes}} || {{No}} ||<br />
|-<br />
| Mycelium || {{Yes}} || {{Yes}} ||<br />
|-<br />
| [https://play.google.com/store/apps/details?id=de.schildbach.wallet Bitcoin Wallet for Android] || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Wasabi Wallet || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Trust Wallet || {{Yes}} || {{Yes}} || [https://trustwallet.com/blog/trust-wallet-adds-support-for-btc-ltc-bch official blog]<br />
|-<br />
| Guarda Wallet || {{Yes}} || {{No}} || [https://twitter.com/GuardaWallet/status/1194270398730448896 twitter announcement]<br />
|-<br />
|}<br />
<br />
=== Hardware Wallets ===<br />
<br />
Hardware wallet manufacturers typically publish a web wallet or browser add-on wallet for use with their hardware. Users can also sometimes connect their hardware wallet to a software wallet like [[Electrum]].<br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Send to !! Create/receive !! Notes<br />
|-<br />
| Trezor web wallet || {{Acceptable|PR Merged}} || {{No}} ||<br />
|-<br />
| Ledger chrome app || {{No}} || {{No}} ||<br />
|-<br />
| Ledger Live (desktop app) || {{Yes}} || {{Yes}} || Experimental feature<br />
|-<br />
| KeepKey chrome app || {{No}} || {{No}} ||<br />
|-<br />
| BitBox Desktop app || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Trezor + Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Ledger + Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| BitBox + Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| KeepKey + Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Archos + Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Coldcard + Electrum || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Ballet + app|| {{Yes}} || {{Yes}} ||<br />
|}<br />
<br />
=== Web Wallets ===<br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Send to !! Create/receive !! Notes<br />
|-<br />
| Coinapult || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| Coin.Space || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| BitGo || {{Yes}} || {{Yes}} || Full support on v2 platform, no plans to add support on v1 platform. Also see: https://blog.bitgo.com/native-segwit-addresses-via-bitgos-api-4946f2007be9<br />
|-<br />
| blockchain.info web|| {{Yes}} || {{No}} || https://twitter.com/provoost/status/1037802325874761728<br />
|-<br />
| HolyTransaction || {{Yes}} || {{No}} ||<br />
|-<br />
| [https://coinb.in Coinb.in] || {{Yes}} || {{Yes}} || open source JavaScript implementation<br />
|-<br />
| Guarda Wallet || {{Yes}} || {{No}} || https://twitter.com/GuardaWallet/status/1194270398730448896<br />
|}<br />
<br />
=== Exchanges ===<br />
<br />
<!-- Exchanges in alphabetical order please --><br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Send to !! Create/receive !! Notes<br />
|-<br />
| 1Fox || {{Yes}} || {{No}} || https://1fox.com/?c=en/content/blog&id=12<br />
|-<br />
| [[AgoraDesk]] || {{Yes}} || {{No}} || <br />
|-<br />
| Anycoin Direct || {{Yes}} || {{No}} || https://anycoindirect.eu/en/news/details/segwit-activated<br />
|-<br />
| BitBargain.co.uk || {{Yes}} || {{No}} ||<br />
|-<br />
| Bitcoin.de || {{Yes}} || {{No}} || https://bitcoinblog.de/2018/08/10/bitcoin-de-aktiviert-segwit-kunden-sparen-gebuehren/<br />
|-<br />
| Bitfinex || {{Yes}} || {{No}} || https://twitter.com/bitfinex/status/1189164144789983234<br />
|-<br />
| BitMEX || {{yes}} || {{No}} || https://blog.bitmex.com/bitmex-enables-bech32-sending-support/<br />
|-<br />
| Bittrex || {{No}} || {{No}} || https://www.reddit.com/r/Bitcoin/comments/gqt1m6/bittrex_does_not_even_support_withdrawals_to/<br />
|-<br />
| Bittylicious || {{Yes}} || {{No}} || https://twitter.com/Bittylicious_/status/998881327347888128<br />
|-<br />
| Bitstamp || {{Yes}} || {{Yes}} || https://www.bitstamp.net/article/weve-added-support-bech32-bitcoin-addresses-bitsta/<br />
|-<br />
| Bitso || {{Yes}} || {{No}} || https://twitter.com/Bitso/status/1203784055340314624?s=20<br />
|-<br />
| Bitwage || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| Bisq || {{No}} || {{No}} || https://github.com/bisq-network/bisq-desktop/issues/1139 https://bisq.community/t/bech32-address-support/6521<br />
|-<br />
| Coinbase.com || {{Yes}} || {{No}} || https://twitter.com/diogorsergio/status/983052769262292992 (Note that Coinbase commerce does not support sending to bech32)<br />
|-<br />
| CoinFalcon || {{Yes}} || {{No}} ||<br />
|-<br />
| Coinfloor || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| Coinsbank.com || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Flyp.me || {{Yes}} || {{No}} ||<br />
|-<br />
| GDax || {{Yes}} || {{No}} || https://www.reddit.com/r/Bitcoin/comments/8c738k/coinbase_gdax_already_allows_sending_to_bc1/<br />
|-<br />
| Gemini || {{Yes}} || {{Yes}} || https://np.reddit.com/r/Bitcoin/comments/b66n0v/psa_gemini_is_full_on_with_native_segwit_and_uses/<br />
|-<br />
| Genesis || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| Globitex || {{No}} || {{No}} ||<br />
|-<br />
| HitBTC || {{Yes}} || {{No}} ||<br />
|-<br />
| Hodl Hodl || {{Yes}} || {{Yes}} || https://medium.com/@hodlhodl/hodl-hodl-segwit-compatible-exchange-a2231968ac56<br />
|-<br />
| Independent Reserve|| {{Yes}} || {{No}} || https://www.independentreserve.com/bitcoin/investing<br />
|-<br />
| Itbit || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| Kraken || {{Yes}} || {{No}} || https://twitter.com/krakenfx/status/1060306827848470528<br />
|-<br />
| LedgerX || {{No}} || {{No}} || <br />
|-<br />
| Liberalcoins || {{Yes}} || {{Yes}} || https://liberalcoins.com<br />
|-<br />
| Localbitcoins.com || {{No}} || {{No}} ||<br />
|-<br />
| Paxful.com || {{Evaluating|??}} || {{No}} ||<br />
|-<br />
| Poloniex.com || {{Yes}} || {{No}} || https://www.reddit.com/r/Bitcoin/comments/a3jhcf/you_can_now_withdraw_from_poloniex_to_bech32/<br />
|-<br />
| TheRockTrading.com || {{Yes}} || {{Yes}} || https://twitter.com/TheRockTrading/status/976787499648512003<br />
|-<br />
| Walltime || {{Yes}} || {{Yes}} || https://walltime.info<br />
|-<br />
| Purse.io || {{Yes}} || {{Yes}} ||<br />
|-<br />
| www.bitwala.com || {{Yes}} || {{Yes}} ||<br />
|-<br />
| Xapo || {{Yes}} || {{No}} ||<br />
|}<br />
<br />
=== Bitcoin ATM Models ===<br />
<br />
Hopefully when a model updates then all its ATMs everywhere will gain that feature. See https://coinatmradar.com/shop/buy-bitcoin-atm/<br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Send to !! Create/receive !! Notes<br />
|-<br />
| GenesisCoin || {{No}} || {{No}} ||<br />
|-<br />
| General Bytes || {{Yes}} || {{Yes}} || Depending on configuration. Since version 20190613 https://www.generalbytes.com/en/support/changelog<br />
|-<br />
| Lamassu Douro || {{Yes}} || {{No}} || https://medium.com/@LamassuSupport/announcing-crafty-chnemu-v7-3-9522fe2868<br />
|}<br />
<br />
=== Blockchain Explorers ===<br />
<br />
For trying these out you can use mainnet TXIDs <code>4ef47f6eb681d5d9fa2f7e16336cd629303c635e8da51e425b76088be9c8744c</code> and <code>514a33f1d46179b89e1fea7bbb07b682ab14083a276979f91038369d1a8d689b</code>. And addresses <code>bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq</code> and <code>bc1qc7slrfxkknqcq2jevvvkdgvrt8080852dfjewde450xdlk4ugp7szw5tk9</code>.<br />
<br />
Some blockchain explorers can only parse the bech32 address and display it, they don't build an index so users cannot search for bech32 addresses.<br />
<br />
See also: https://en.bitcoin.it/wiki/Category:Block_chain_browsers<br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Display !! Index !! Notes<br />
|-<br />
| Apirone.com || {{Yes}} || {{Yes}} || https://apirone.com<br />
|-<br />
| bitaps.com || {{Yes}} || {{Yes}} || https://bitaps.com<br />
|-<br />
| Bitflyer || {{Yes}} || {{Yes}} || https://chainflyer.bitflyer.jp/<br />
|-<br />
| Bitupper Explorer || {{Yes}} || {{Yes}} || https://bitupper.com/en/explorer/bitcoin<br />
|-<br />
| blockchain.info || {{Yes}} || {{No}} ||<br />
|-<br />
| Blockchair || {{Yes}} || {{Yes}} || https://blockchair.com/<br />
|-<br />
| Blockcypher || {{Yes}} || {{Yes}} || https://live.blockcypher.com/btc<br />
|-<br />
| Blockonomics || {{Yes}} || {{Yes}} || https://www.blockonomics.co<br />
|-<br />
| Blockpath || {{Yes}} || {{Yes}} || https://blockpath.com<br />
|-<br />
| BTC.com || {{Yes}} || {{Yes}} || https://BTC.com<br />
|-<br />
| Esplora || {{Yes}} || {{Yes}} || Open source explorer, instances are https://blockstream.info/ and https://www.localbitcoinschain.com/<br />
|-<br />
| chaindex || {{Yes}} || {{Yes}} || https://chaindex.com/blockchain/<br />
|-<br />
| Insight || {{No}} || {{No}} || Open source explorer, instances include https://insight.bitpay.com/<br />
|-<br />
| OXT || {{Yes}} || {{Yes}} || https://oxt.me/<br />
|-<br />
| Tradeblock || {{No}} || {{No}} || https://tradeblock.com/bitcoin<br />
|}<br />
<br />
=== Payment Processors ===<br />
<br />
<!-- Payment processors in alphabetical order please --><br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Invoice addresses !! Withdrawal addresses !! Notes<br />
|-<br />
| [https://apirone.com Apirone] || {{Yes}} || {{Yes}} || Payment notifications, merchant dashboard, plugins for Magento, WooCommerce, OpenCart 2, Opencart 3.x, Virtuemart<br />
|-<br />
| [https://bitaps.com Bitaps] || {{Yes}} || {{Yes}} || Payment forwarding API, Wallet API, fault tolerance callback.<br />
|-<br />
| [https://coingate.com CoinGate] || {{No}} || {{Yes}} ||<br />
|-<br />
| [https://cryptochill.com CryptoChill] || {{Yes}} || {{Yes}} || Highly customizable Bitcoin and Lightning Network payment gateway. Multi-sig, HD wallets, API, SDK.<br />
|}<br />
<br />
=== Mining Pools ===<br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Payout !! Notes<br />
|-<br />
| [https://pool.btc.com/ BTC.com Pool] || {{No}} || <br />
|-<br />
| [http://ckpool.org/ Ckpool] || {{Yes}} || <br />
|-<br />
| [https://kano.is/ KanoPool] || {{Yes}} || [https://bitcointalk.org/index.php?topic=789369.msg53374508#msg53374508 bitcointalk source]<br />
|-<br />
| [http://poolin.com/ Poolin] || {{Yes}} || [https://bitcointalk.org/index.php?topic=5169994.msg52184844#msg52184844 bitcointalk source]<br />
|-<br />
| [https://slushpool.com/ Slush Pool] || {{Yes}} ||<br />
|-<br />
| [https://ukrpool.com/ Ukr Pool] || {{Yes}} || [https://bitcointalk.org/index.php?topic=5124825.msg51358033#msg51358033 bitcointalk source]<br />
|-<br />
| [https://pool.viabtc.com/ ViaBTC Pool] || {{No}} ||<br />
|}<br />
<br />
<!--<br />
<br />
=== Other Services ===<br />
<br />
Casinos, marketplaces, etc that let users withdraw money<br />
<br />
{| class="wikitable sortable"<br />
|-<br />
! Name !! Withdrawals !! Notes<br />
|-<br />
| 1Broker || {{Yes}} || <br />
|-<br />
| [https://crypto.games Crypto.Games]|| {{Yes}} || [https://bitcointalk.org/index.php?topic=750760.msg31421151#msg31421151 bitcointalk source]<br />
|-<br />
| YOLOdice || {{Yes}} ||<br />
|}<br />
<br />
--><br />
<br />
=== References ===<br />
<br />
[[Category:Software]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Scalability&diff=68030Scalability2020-06-27T13:12:18Z<p>Furunodo: </p>
<hr />
<div>'''''Note: This page is seriously outdated and largely unmaintained; due to past incidents of edit-warring it has not been subject to much peer review.'''''<br />
<br />
A Bitcoin [[full node]] could be modified to scale to much higher transaction rates than are seen today, assuming that said node is running on a high end servers rather than a desktop. Bitcoin was designed to support lightweight clients that only process small parts of the block chain (see ''simplified payment verification'' below for more details on this).<br />
<br />
''Please note that this page exists to give calculations about the scalability of a Bitcoin full node and transactions on the block chain without regards to network security and decentralization. It is not intended to discuss the scalability of alternative protocols or try and summarise philosophical debates. Create alternative pages if you want to do that.''<br />
<br />
==Note to Readers==<br />
<br />
When techies hear about how bitcoin works they frequently stop at the word "flooding" and say "Oh-my-god! that can't scale!". The purpose of this article is to take an extreme example, the peak transaction rate of Visa, and show that bitcoin ''could'' technically reach that kind of rate without any kind of questionable reasoning, changes in the core design, or non-existent overlays. As such, it's merely an extreme example— not a plan for how bitcoin will grow to address wider needs (as a decentralized system it is the bitcoin using public who will decide how bitcoin grows)— it's just an argument that shows that bitcoin's core design can scale much better than an intelligent person might guess at first.<br />
<br />
Dan rightly criticizes the analysis presented here— pointing out that operating at this scale would significantly reduce the decentralized nature of bitcoin: If you have to have many terabytes of disk space to run a "full validating" node then fewer people will do it, and everyone who doesn't will have to trust the ones who do to be honest. Dan appears (from his slides) to have gone too far with that argument: he seems to suggest that this means bitcoins will be controlled by the kind of central banks that are common today. His analysis fails for two reasons (and the second is the fault of this page being a bit misleading):<br />
<br />
First, even at the astronomic scale presented here the required capacity is well within the realm of (wealthy) private individuals, and certainly would be at some future time when that kind of capacity was required. A system which puts private individuals, or at least small groups of private parties, on equal footing with central banks could hardly be called a centralized one, though it would be less decentralized than the bitcoin we have today. The system could also not get to this kind of scale without bitcoin users agreeing collectively to increase the maximum block size, so it's not an outcome that can happen without the consent of bitcoin users.<br />
<br />
Second, and most importantly, the assumed scaling described here deals with Bitcoin replacing visa. This is a poor comparison because bitcoin alone is not a perfect replacement for visa for reasons completely unrelated to scaling: Bitcoin does not offer instant transactions, credit, or various anti-fraud mechanisms (which some people want, even if not everyone does), for example. Bitcoin is a more complete replacement for checks, wire transfers, money orders, gold coins, CDs, savings accounts, etc. and if widely adopted probably replace the uses of credit cards which would be better served by these other things if they worked better online.<br />
<br />
Bitcoin users sometimes gloss over this fact too quickly because people are too quick to call it a flaw but this is unfair. No one system is ideal for all usage and Bitcoin has a broader spectrum of qualities than most monetary instruments. If the bitcoin community isn't willing to point out some things would better be done by other systems then it becomes easy to make strawman arguments: If we admit that bitcoin could be used as a floor wax and desert topping, someone will always point out that it's not the best floorwax or best desert topping.<br />
<br />
It's trivial to build payment processing and credit systems _on top_ of bitcoin, both classic ones (like Visa itself!) as well as self-proclaimed "decentralized" ones like Ripple. These systems could handle higher transaction volumes with lower costs, and settle frequently to the bitcoin that backs them. These could use other techniques with different tradeoffs than bitcoin, but still be backed and denominated by bitcoin so still enjoy its lack of central control. We see the beginnings of this today with bitcoin exchange and wallet services allowing instant payments between members.<br />
<br />
These services would gain the benefit of the stable inflation resistant bitcoin currency, users would gain the benefits of instant transactions, credit, and anti-fraud, bitcoin overall would enjoy improved scaling from offloaded transaction volume without compromising its decentralized nature. In a world where bitcoin was widely used payment processing systems would probably have lower prices because they would need to compete with raw-bitcoin transactions, they also could be afford lower price because frequent bitcoin settling (and zero trust bitcoin escrow transactions) would reduce their risk. This is doubly true because bitcoin could conceivably scale to replace them entirely, even if that wouldn't be the best idea due to the resulting reduction in decentralization.<br />
<br />
==Scalability targets==<br />
<br />
VISA handles on average around 2,000 transactions per second (tps), so call it a daily peak rate of 4,000 tps. It has a peak capacity of around 56,000 transactions per second, [https://usa.visa.com/dam/VCOM/download/corporate/media/visa-fact-sheet-Jun2015.pdf] however they never actually use more than about a third of this even during peak shopping periods. [http://www.visa.com/blogarchives/us/2013/10/10/stress-test-prepares-visanet-for-the-most-wonderful-time-of-the-year/index.html]<br />
<br />
PayPal, in contrast, handled around 10 million transactions per day for an average of 115 tps in late 2014. [https://web.archive.org/web/20141226073503/https://www.paypal-media.com/about]<br />
<br />
Let's take 4,000 tps as starting goal. Obviously if we want Bitcoin to scale to all economic transactions worldwide, including cash, it'd be a lot higher than that, perhaps more in the region of a few hundred thousand tps. And the need to be able to withstand DoS attacks (which VISA does not have to deal with) implies we would want to scale far beyond the standard peak rates. Still, picking a target let us do some basic calculations even if it's a little arbitrary.<br />
<br />
Today the Bitcoin network is restricted to a sustained rate of 7 tps due to the bitcoin protocol restricting block sizes to 1MB.<br />
<br />
===CPU===<br />
<br />
The protocol has two parts. Nodes send "inv" messages to other nodes telling them they have a new transaction. If the receiving node doesn't have that transaction it requests it with a getdata.<br />
<br />
The big cost is the crypto and block chain lookups involved with verifying the transaction. Verifying a transaction means some hashing and some [[ECDSA]] signature verifications. RIPEMD-160 runs at 106 megabytes/sec (call it 100 for simplicity) and SHA256 is about the same. So hashing 1 megabyte should take around 10 milliseconds and hashing 1 kilobyte would take 0.01 milliseconds - fast enough that we can ignore it.<br />
<br />
Bitcoin is currently able (with a couple of simple optimizations that are prototyped but not merged yet) to perform around 8000 signature verifications per second on an quad core [http://ark.intel.com/products/53469 Intel Core i7-2670QM 2.2Ghz processor]. The average number of inputs per transaction is around 2, so we must halve the rate. This means 4000 tps is easily achievable CPU-wise with a single fairly mainstream CPU.<br />
<br />
As we can see, this means as long as Bitcoin nodes are allowed to max out at least 4 cores of the machines they run on, we will not run out of CPU capacity for signature checking unless Bitcoin is handling 100 times as much traffic as PayPal. As of late 2015 the network is handling 1.5 transactions/second, so even assuming enormous growth in popularity we will not reach this level for a long time.<br />
<br />
Of course Bitcoin does other things beyond signature checking, most obviously, managing the database. We use LevelDB which does the bulk of the heavy lifting on a separate thread, and is capable of very high read/write loads. Overall Bitcoin's CPU usage is dominated by ECDSA.<br />
<br />
===Network===<br />
<br />
Let's assume an average rate of 2000tps, so just VISA. Transactions vary in size from about 0.2 kilobytes to over 1 kilobyte, but it's averaging half a kilobyte today.<br />
<br />
That means that you need to keep up with around 8 megabits/second of transaction data (2000tps * 512 bytes) / 1024 bytes in a kilobyte / 1024 kilobytes in a megabyte = 0.97 megabytes per second * 8 = 7.8 megabits/second.<br />
<br />
This sort of bandwidth is already common for even residential connections today, and is certainly at the low end of what colocation providers would expect to provide you with.<br />
<br />
When blocks are solved, the current protocol will send the transactions again, even if a peer has already seen it at broadcast time. Fixing this to make blocks just list of hashes would resolve the issue and make the bandwidth needed for block broadcast negligable. So whilst this optimization isn't fully implemented today, we do not consider block transmission bandwidth here.<br />
<br />
===Storage===<br />
<br />
At very high transaction rates each block can be over half a gigabyte in size.<br />
<br />
It is not required for most fully validating nodes to store the entire chain. In Satoshi's paper he describes "pruning", a way to delete unnecessary data about transactions that are fully spent. This reduces the amount of data that is needed for a fully validating node to be only the size of the current unspent output size, plus some additional data that is needed to handle re-orgs. As of October 2012 (block 203258) there have been 7,979,231 transactions, however the size of the unspent output set is less than 100MiB, which is small enough to easily fit in RAM for even quite old computers.<br />
<br />
Only a small number of archival nodes need to store the full chain going back to the genesis block. These nodes can be used to bootstrap new fully validating nodes from scratch but are otherwise unnecessary.<br />
<br />
The primary limiting factor in Bitcoin's performance is disk seeks once the unspent transaction output set stops fitting in memory. Once hard disks are phased out in favour of SSDs, it is quite possible that access to the [[UTXO]] set never becomes a serious bottleneck.<br />
<br />
==Optimizations==<br />
<br />
The description above applies to the current software with only minor optimizations assumed (the type that can and have been done by one man in a few weeks). <br />
<br />
However there is potential for even greater optimizations to be made in future, at the cost of some additional complexity.<br />
<br />
===CPU===<br />
<br />
Algorithms exist to accelerate batch verification over elliptic curve signatures. It's possible to check their signatures simultaneously for a 2x speedup. This is a somewhat more complex implementation.<br />
<br />
===Simplified payment verification===<br />
<!-- "Simplified payment verification" redirects here. Update the redirect if you change the section title --><br />
<br />
It's possible to build a Bitcoin implementation that does not verify everything, but instead relies on either connecting to a trusted node, or puts its faith in high difficulty as a proxy for proof of validity. [[bitcoinj]] is an implementation of this mode.<br />
<br />
In Simplified Payment Verification (SPV) mode, named after the section of Satoshi's paper that describes it, clients connect to an arbitrary full node and download only the block headers. They verify the chain headers connect together correctly and that the difficulty is high enough. They then request transactions matching particular patterns from the remote node (ie, payments to your addresses), which provides copies of those transactions along with a Merkle branch linking them to the block in which they appeared. This exploits the Merkle tree structure to allow proof of inclusion without needing the full contents of the block. <br />
<br />
As a further optimization, block headers that are buried sufficiently deep can be thrown away after some time (eg. you only really need to store as low as 2016 headers).<br />
<br />
The level of difficulty required to obtain confidence the remote node is not feeding you fictional transactions depends on your threat model. If you are connecting to a node that is known to be reliable, the difficulty doesn't matter. If you want to pick a random node, the cost for an attacker to mine a block sequence containing a bogus transaction should be higher than the value to be obtained by defrauding you. By changing how deeply buried the block must be, you can trade off confirmation time vs cost of an attack.<br />
<br />
Programs implementing this approach can have fixed storage/network overhead in the null case of no usage, and resource usage proportional to received/sent transactions.<br />
<br />
See also: [[Thin Client Security]].<br />
<br />
== Related work ==<br />
There are a few proposals for optimizing Bitcoin's scalability. Some of these require an alt-chain / hard fork.<br />
<br />
* [https://bitcointalk.org/index.php?topic=88208.0 Ultimate blockchain compression] - the idea that the blockchain can be compressed to achieve "trust-free lite nodes"<br />
* [http://cryptonite.info/files/mbc-scheme-rev2.pdf The Finite Blockchain] paper that describes splitting the blockchain into three data structures, each better suited for its purpose. The three data structures are a finite blockchain (keep N blocks into the past), an "account tree" which keeps account balance for every address with a non-zero balance, and a "proof chain" which is an (ever growing) slimmed down version of the blockchain.<br />
* [https://lightning.network/ Lightning Network], an alternative protocol for transaction clearance in which nodes set up micropayment channels between each other and settle up on the block chain occasionally. Ordinary users interact primarily or only with payment channels and only use the blockchain for large transfers and cold storage.<br />
<br />
[[Category:Technical]]<br />
[[Category:Scalability]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Scalability&diff=68029Scalability2020-06-27T13:05:27Z<p>Furunodo: </p>
<hr />
<div>[Note: This page is seriously outdated and largely unmaintained; due to past incidents of edit-warring it has not been subject to much peer review.]<br />
<br />
A Bitcoin full node could be modified to scale to much higher transaction rates than are seen today, assuming that said node is running on a high end servers rather than a desktop. Bitcoin was designed to support lightweight clients that only process small parts of the block chain (see ''simplified payment verification'' below for more details on this).<br />
<br />
''Please note that this page exists to give calculations about the scalability of a Bitcoin full node and transactions on the block chain without regards to network security and decentralization. It is not intended to discuss the scalability of alternative protocols or try and summarise philosophical debates. Create alternative pages if you want to do that.''<br />
<br />
==Note to Readers==<br />
<br />
When techies hear about how bitcoin works they frequently stop at the word "flooding" and say "Oh-my-god! that can't scale!". The purpose of this article is to take an extreme example, the peak transaction rate of Visa, and show that bitcoin ''could'' technically reach that kind of rate without any kind of questionable reasoning, changes in the core design, or non-existent overlays. As such, it's merely an extreme example— not a plan for how bitcoin will grow to address wider needs (as a decentralized system it is the bitcoin using public who will decide how bitcoin grows)— it's just an argument that shows that bitcoin's core design can scale much better than an intelligent person might guess at first.<br />
<br />
Dan rightly criticizes the analysis presented here— pointing out that operating at this scale would significantly reduce the decentralized nature of bitcoin: If you have to have many terabytes of disk space to run a "full validating" node then fewer people will do it, and everyone who doesn't will have to trust the ones who do to be honest. Dan appears (from his slides) to have gone too far with that argument: he seems to suggest that this means bitcoins will be controlled by the kind of central banks that are common today. His analysis fails for two reasons (and the second is the fault of this page being a bit misleading):<br />
<br />
First, even at the astronomic scale presented here the required capacity is well within the realm of (wealthy) private individuals, and certainly would be at some future time when that kind of capacity was required. A system which puts private individuals, or at least small groups of private parties, on equal footing with central banks could hardly be called a centralized one, though it would be less decentralized than the bitcoin we have today. The system could also not get to this kind of scale without bitcoin users agreeing collectively to increase the maximum block size, so it's not an outcome that can happen without the consent of bitcoin users.<br />
<br />
Second, and most importantly, the assumed scaling described here deals with Bitcoin replacing visa. This is a poor comparison because bitcoin alone is not a perfect replacement for visa for reasons completely unrelated to scaling: Bitcoin does not offer instant transactions, credit, or various anti-fraud mechanisms (which some people want, even if not everyone does), for example. Bitcoin is a more complete replacement for checks, wire transfers, money orders, gold coins, CDs, savings accounts, etc. and if widely adopted probably replace the uses of credit cards which would be better served by these other things if they worked better online.<br />
<br />
Bitcoin users sometimes gloss over this fact too quickly because people are too quick to call it a flaw but this is unfair. No one system is ideal for all usage and Bitcoin has a broader spectrum of qualities than most monetary instruments. If the bitcoin community isn't willing to point out some things would better be done by other systems then it becomes easy to make strawman arguments: If we admit that bitcoin could be used as a floor wax and desert topping, someone will always point out that it's not the best floorwax or best desert topping.<br />
<br />
It's trivial to build payment processing and credit systems _on top_ of bitcoin, both classic ones (like Visa itself!) as well as self-proclaimed "decentralized" ones like Ripple. These systems could handle higher transaction volumes with lower costs, and settle frequently to the bitcoin that backs them. These could use other techniques with different tradeoffs than bitcoin, but still be backed and denominated by bitcoin so still enjoy its lack of central control. We see the beginnings of this today with bitcoin exchange and wallet services allowing instant payments between members.<br />
<br />
These services would gain the benefit of the stable inflation resistant bitcoin currency, users would gain the benefits of instant transactions, credit, and anti-fraud, bitcoin overall would enjoy improved scaling from offloaded transaction volume without compromising its decentralized nature. In a world where bitcoin was widely used payment processing systems would probably have lower prices because they would need to compete with raw-bitcoin transactions, they also could be afford lower price because frequent bitcoin settling (and zero trust bitcoin escrow transactions) would reduce their risk. This is doubly true because bitcoin could conceivably scale to replace them entirely, even if that wouldn't be the best idea due to the resulting reduction in decentralization.<br />
<br />
==Scalability targets==<br />
<br />
VISA handles on average around 2,000 transactions per second (tps), so call it a daily peak rate of 4,000 tps. It has a peak capacity of around 56,000 transactions per second, [https://usa.visa.com/dam/VCOM/download/corporate/media/visa-fact-sheet-Jun2015.pdf] however they never actually use more than about a third of this even during peak shopping periods. [http://www.visa.com/blogarchives/us/2013/10/10/stress-test-prepares-visanet-for-the-most-wonderful-time-of-the-year/index.html]<br />
<br />
PayPal, in contrast, handled around 10 million transactions per day for an average of 115 tps in late 2014. [https://web.archive.org/web/20141226073503/https://www.paypal-media.com/about]<br />
<br />
Let's take 4,000 tps as starting goal. Obviously if we want Bitcoin to scale to all economic transactions worldwide, including cash, it'd be a lot higher than that, perhaps more in the region of a few hundred thousand tps. And the need to be able to withstand DoS attacks (which VISA does not have to deal with) implies we would want to scale far beyond the standard peak rates. Still, picking a target let us do some basic calculations even if it's a little arbitrary.<br />
<br />
Today the Bitcoin network is restricted to a sustained rate of 7 tps due to the bitcoin protocol restricting block sizes to 1MB.<br />
<br />
===CPU===<br />
<br />
The protocol has two parts. Nodes send "inv" messages to other nodes telling them they have a new transaction. If the receiving node doesn't have that transaction it requests it with a getdata.<br />
<br />
The big cost is the crypto and block chain lookups involved with verifying the transaction. Verifying a transaction means some hashing and some [[ECDSA]] signature verifications. RIPEMD-160 runs at 106 megabytes/sec (call it 100 for simplicity) and SHA256 is about the same. So hashing 1 megabyte should take around 10 milliseconds and hashing 1 kilobyte would take 0.01 milliseconds - fast enough that we can ignore it.<br />
<br />
Bitcoin is currently able (with a couple of simple optimizations that are prototyped but not merged yet) to perform around 8000 signature verifications per second on an quad core [http://ark.intel.com/products/53469 Intel Core i7-2670QM 2.2Ghz processor]. The average number of inputs per transaction is around 2, so we must halve the rate. This means 4000 tps is easily achievable CPU-wise with a single fairly mainstream CPU.<br />
<br />
As we can see, this means as long as Bitcoin nodes are allowed to max out at least 4 cores of the machines they run on, we will not run out of CPU capacity for signature checking unless Bitcoin is handling 100 times as much traffic as PayPal. As of late 2015 the network is handling 1.5 transactions/second, so even assuming enormous growth in popularity we will not reach this level for a long time.<br />
<br />
Of course Bitcoin does other things beyond signature checking, most obviously, managing the database. We use LevelDB which does the bulk of the heavy lifting on a separate thread, and is capable of very high read/write loads. Overall Bitcoin's CPU usage is dominated by ECDSA.<br />
<br />
===Network===<br />
<br />
Let's assume an average rate of 2000tps, so just VISA. Transactions vary in size from about 0.2 kilobytes to over 1 kilobyte, but it's averaging half a kilobyte today.<br />
<br />
That means that you need to keep up with around 8 megabits/second of transaction data (2000tps * 512 bytes) / 1024 bytes in a kilobyte / 1024 kilobytes in a megabyte = 0.97 megabytes per second * 8 = 7.8 megabits/second.<br />
<br />
This sort of bandwidth is already common for even residential connections today, and is certainly at the low end of what colocation providers would expect to provide you with.<br />
<br />
When blocks are solved, the current protocol will send the transactions again, even if a peer has already seen it at broadcast time. Fixing this to make blocks just list of hashes would resolve the issue and make the bandwidth needed for block broadcast negligable. So whilst this optimization isn't fully implemented today, we do not consider block transmission bandwidth here.<br />
<br />
===Storage===<br />
<br />
At very high transaction rates each block can be over half a gigabyte in size.<br />
<br />
It is not required for most fully validating nodes to store the entire chain. In Satoshi's paper he describes "pruning", a way to delete unnecessary data about transactions that are fully spent. This reduces the amount of data that is needed for a fully validating node to be only the size of the current unspent output size, plus some additional data that is needed to handle re-orgs. As of October 2012 (block 203258) there have been 7,979,231 transactions, however the size of the unspent output set is less than 100MiB, which is small enough to easily fit in RAM for even quite old computers.<br />
<br />
Only a small number of archival nodes need to store the full chain going back to the genesis block. These nodes can be used to bootstrap new fully validating nodes from scratch but are otherwise unnecessary.<br />
<br />
The primary limiting factor in Bitcoin's performance is disk seeks once the unspent transaction output set stops fitting in memory. Once hard disks are phased out in favour of SSDs, it is quite possible that access to the [[UTXO]] set never becomes a serious bottleneck.<br />
<br />
==Optimizations==<br />
<br />
The description above applies to the current software with only minor optimizations assumed (the type that can and have been done by one man in a few weeks). <br />
<br />
However there is potential for even greater optimizations to be made in future, at the cost of some additional complexity.<br />
<br />
===CPU===<br />
<br />
Algorithms exist to accelerate batch verification over elliptic curve signatures. It's possible to check their signatures simultaneously for a 2x speedup. This is a somewhat more complex implementation.<br />
<br />
===Simplified payment verification===<br />
<!-- "Simplified payment verification" redirects here. Update the redirect if you change the section title --><br />
<br />
It's possible to build a Bitcoin implementation that does not verify everything, but instead relies on either connecting to a trusted node, or puts its faith in high difficulty as a proxy for proof of validity. [[bitcoinj]] is an implementation of this mode.<br />
<br />
In Simplified Payment Verification (SPV) mode, named after the section of Satoshi's paper that describes it, clients connect to an arbitrary full node and download only the block headers. They verify the chain headers connect together correctly and that the difficulty is high enough. They then request transactions matching particular patterns from the remote node (ie, payments to your addresses), which provides copies of those transactions along with a Merkle branch linking them to the block in which they appeared. This exploits the Merkle tree structure to allow proof of inclusion without needing the full contents of the block. <br />
<br />
As a further optimization, block headers that are buried sufficiently deep can be thrown away after some time (eg. you only really need to store as low as 2016 headers).<br />
<br />
The level of difficulty required to obtain confidence the remote node is not feeding you fictional transactions depends on your threat model. If you are connecting to a node that is known to be reliable, the difficulty doesn't matter. If you want to pick a random node, the cost for an attacker to mine a block sequence containing a bogus transaction should be higher than the value to be obtained by defrauding you. By changing how deeply buried the block must be, you can trade off confirmation time vs cost of an attack.<br />
<br />
Programs implementing this approach can have fixed storage/network overhead in the null case of no usage, and resource usage proportional to received/sent transactions.<br />
<br />
See also: [[Thin Client Security]].<br />
<br />
== Related work ==<br />
There are a few proposals for optimizing Bitcoin's scalability. Some of these require an alt-chain / hard fork.<br />
<br />
* [https://bitcointalk.org/index.php?topic=88208.0 Ultimate blockchain compression] - the idea that the blockchain can be compressed to achieve "trust-free lite nodes"<br />
* [http://cryptonite.info/files/mbc-scheme-rev2.pdf The Finite Blockchain] paper that describes splitting the blockchain into three data structures, each better suited for its purpose. The three data structures are a finite blockchain (keep N blocks into the past), an "account tree" which keeps account balance for every address with a non-zero balance, and a "proof chain" which is an (ever growing) slimmed down version of the blockchain.<br />
* [https://lightning.network/ Lightning Network], an alternative protocol for transaction clearance in which nodes set up micropayment channels between each other and settle up on the block chain occasionally. Ordinary users interact primarily or only with payment channels and only use the blockchain for large transfers and cold storage.<br />
<br />
[[Category:Technical]]<br />
[[Category:Scalability]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=UTXO&diff=68028UTXO2020-06-27T12:57:14Z<p>Furunodo: </p>
<hr />
<div>'''UTXO''' stands for Unspent Transaction (TX) Output. Every on-chain bitcoin [[transaction]] sends bitcoin to one or more [[address]]es, from at least zero (in case of a [[coinbase]] transcation) addresses.<br />
<br />
A bitcoin [[wallet]] balance is actually the sum of the UTXOs controlled by the wallet's private keys.<br />
<br />
== UTXO set ==<br />
<br />
The ''UTXO set'' is the collection of all addresses with unspent outputs.<br />
<br />
{{stub}}<br />
<br />
[[Category:Technical]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Courses&diff=68027Courses2020-06-27T12:55:25Z<p>Furunodo: </p>
<hr />
<div>; Videos<br />
<br />
; Documentation<br />
WP, Bitcoin.it wiki, BTC developer guide<br />
Translate the wiki, guide, and code docs! Prioritize. //<br />
<br />
Books: Mastering, ...<br />
<br />
; News summaries<br />
Best ones not easily available to newbies<br />
<br />
; Source code guides<br />
<br />
; Successful dev meetups and mentorships<br />
* Bitdevs, especially NYC<br />
<br />
== Current blockchain courses ==<br />
Online: Coursera (but what's the sequence of math, cs, econ, game theory, finance?<br />
<br />
In person: Berkeley, Ecole Normale; residencies (Chaincode ++)<br />
<br />
Can we bring in great visualizers & animators?<br />
<br />
== Background course sequence ==<br />
Core math | Programming exercises | Game theory | Security | OS/Git basics | Contracts<br />
<br />
<br />
<!--<br />
Videos - http://www.3blue1brown.com/, YT...<br />
StackExchange, btc.core slack, IRC<br />
Lopp.net? Google for reading lists? (kanzure++ :)<br />
<br />
Reading sourcecode: BTC has lots coping with [[UTXO]] size; not an ideal first step<br />
Early test projects & contribs? Mentorship?<br />
<br />
Difficulty to learn: >1y to contribute.<br />
Dev taking 9 mo, still not able to contribute. 20y C dev, after 4y barely comfortable crafting own txn from scratch.<br />
<br />
Bitcoin koans; Hackerrank for crypto; diverse & universal contributions, students, orgs<br />
Implement Stupidity as complement to solidity & simplicity<br />
Examples : BitDevs in NYC! Lots about blockchain, solidity; not so much about BTC.<br />
Encourages getting everyone to dive in and talk; unlike SF presentation. [go and learn from them]<br />
Open laptops and hack! (SF bitdevs tried this for a while, during Mission20 -- what happened to it?)<br />
Training subsidies? corporate subsidies? for new tech.<br />
Plenty of expensive courses (Berkeley $4k/wk?)<br />
--></div>Furunodohttps://en.bitcoin.it/w/index.php?title=Sweepprivkey_proposal&diff=68026Sweepprivkey proposal2020-06-27T12:55:17Z<p>Furunodo: </p>
<hr />
<div>'''sweepprivkey''' is a PROPOSED Bitcoin RPC command that, given a Bitcoin private key, allows sweeping of some or all of the funds to another address.<br />
Despite this specification, this proposal has never been implemented, and cannot be considered for inclusion until it is.<br />
<br />
This function is useful for merchants who wish to accept typed or scanned Bitcoin private keys as payments, without imposing any specific methodology on how the payments must be processed. ''sweepprivkey'' has no direct effect on anything in the local wallet or transaction history -- the function simply generates a transaction in real-time to sweep the funds to another address, and broadcasts it. That destination address may or may not be in the local wallet.<br />
<br />
The local wallet is only affected if the destination address is in the wallet, and only in an indirect sense: the wallet reacts to the sudden presence of a new transaction referencing it, just the same as if that transaction had been received from a peer.<br />
<br />
This allows merchants to offer a "deposit by private key" method with trivial effort, specifically without having to create a separate deposit implementation for accepting the keys. The merchant can simply expose a way for users to submit private keys, which can then be passed to ''sweepprivkey'' with minimal validation along with the same deposit address that the merchant would normally have given to their customer in anticipation of payment.<br />
<br />
Once the customer has entered a private key and allowed a sweep to take place, the merchant from its perspective will see what looks like a deposit with zero confirmations, and can treat it exactly the same as a normal deposit from outside (including requiring the customer to wait for confirmations as usual, where applicable).<br />
<br />
==Usage==<br />
<br />
The syntax of ''sweepprivkey'' is as follows:<br />
<br />
sweepprivkey <privkey> <minconfirms> [<destinationtype> <destination>] [<fee>] [<amount> <changeaddress>]<br />
<br />
*''privkey'' is required. It can be in any private key format normally accepted for wallet imports with the [[importprivkey]] function.<br />
*''minconfirms'' determines how many confirmations the private key's prior transactions must have before they are considered eligible for being swept. Transactions having less than the minimum confirmations will be ignored. If this is 0, then ''sweepprivkey'' will also attempt to sweep unconfirmed transactions from the in-memory pool.<br />
*''destinationtype'' is either the word ''"address"'' or ''"account"'', and indicates what ''destination'' is. ''"address"'' means sweep funds to another Bitcoin address, and ''"account"'' will perform a ''[[getnewaddress]]'' operation to get an address on the local wallet and sweep the funds there. ''destinationtype'' and ''destination'' are optional, but must both be present together when used. If these are absent, the command is treated as a simple query which returns the total funds available to the private key.<br />
*''destination'' is either a Bitcoin address (if ''destinationtype'' is ''"address"''), or is an account name (if ''destinationtype'' is ''"account"''). Funds are sent here.<br />
*''fee'' is optional, but must be provided if ''amount'' is provided (so that the command knows which parameter is which). This determines how much of a transaction fee to pay. This can be either an amount, or the word ''"default"'', or the word ''"minimum"''. ''Default'' means to pay the transaction fee configured in the bitcoin client, and is the choice assumed if omitted. ''Minimum'' means to pay the minimum fee that the client believes will be required to ensure that the transaction is relayed by the network (which is based on the transaction's age, size, and other factors - see [[GetMinFee]]). In many cases, the fee may be zero. If you specify an amount but it is below the minimum, or the private key doesn't have a balance large enough to meet the minimum, the command reports failure. Fees are always paid from the funds held by the swept private key, not the wallet.<br />
*''amount'' and ''changeaddress'' are optional. When not present, the command will attempt to sweep all funds available via the private key to the extent those funds have enough confirmations to satisfy ''minconfirms''. If an amount is present, the command will only sweep that amount, reporting a failure if amount (plus fee) is greater than the funds available. If the private key contains funds that satisfy ''minconfirms'' as well as funds that do not, only the sufficiently confirmed funds are swept. If a specific amount is requested and a transaction fee must be paid, it will be deducted out of the change rather than the requested transfer amount (FIXME: this seems irrational). ''changeaddress'' address specifies a destination for any leftover change that may be the result of sweeping a partial amount. Not all partial-balance transactions will generate change, particularly if the private key's received amount satisfies exactly the sweep amount. If there is no change, the change address is ignored.<br />
<br />
==Proposed flowchart==<br />
The ''sweepprivkey'' function depends on the ability to quickly find transactions in the [[UTXO]] set controlled by a given private key; simply, a UTXO index on scriptPubKey.<br />
<br />
When the ''sweepprivkey'' command is run, bitcoind will:<br />
<br />
# Ensure the necessary UTXO index is being maintained. If not, it will be built before continuing.<br />
# Find the UTXO which is assigned to a standard scriptPubKey redeemable with only the given private key, and ensure it is buried under enough blocks to satisfy the desired level of ''minconfirms''.<br />
# Confirm that, if ''amount'' is specified, the amount received is equal to or greater than it.<br />
# Do getnewaddress if a wallet account was specified.<br />
# Construct a new transaction in memory that spends funds from the found UTXO to the destination address and, if necessary, the change address. Sign the transaction with ''privkey''.<br />
# Treat the signed transaction the same as if it had come from a peer, including relaying it to all connected peers.<br />
# Return success with the txid and (if applicable) the new address that was gathered via ''getnewaddress''.</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Bitcoin_Core_0.11_(ch_2):_Data_Storage&diff=68025Bitcoin Core 0.11 (ch 2): Data Storage2020-06-27T12:54:29Z<p>Furunodo: </p>
<hr />
<div><br />
This page describes how & where Bitcoin Core stores [[blockchain]] data. <br />
<br />
==Overview==<br />
<br />
There are basically four pieces of data that are maintained:<br />
<br />
: '''blocks/blk*.dat:''' the actual Bitcoin blocks, in network format, dumped in raw on disk. They are only needed for rescanning missing transactions in a wallet, reorganizing to a different part of the chain, and serving the block data to other nodes that are synchronizing.<br />
<br />
: '''blocks/index/*:''' this is a LevelDB database that contains metadata about all known blocks, and where to find them on disk. Without this, finding a block would be very slow.<br />
<br />
: '''chainstate/*:''' this is a LevelDB database with a compact representation of all currently unspent transaction outputs and some metadata about the transactions they are from. The data here is necessary for validating new incoming blocks and transactions. It can theoretically be rebuilt from the block data (see the -reindex command line option), but this takes a rather long time. Without it, you could still theoretically do validation indeed, but it would mean a full scan through the blocks (7 GB as of may 2013) for every output being spent.<br />
<br />
: '''blocks/rev*.dat:''' these contain "undo" data. You can see blocks as 'patches' to the chain state (they consume some unspent outputs, and produce new ones), and see the undo data as reverse patches. They are necessary for rolling back the chainstate, which is necessary in case of reorganisations.<br />
<br />
Note that the LevelDB's are redundant in the sense that they can be rebuilt from the block data. But validation and other operations would become intolerably slow without them.<br />
<br />
See here: [http://bitcoin.stackexchange.com/questions/11104/what-is-the-database-for?rq=1 StackExchange post by Pieter Wuille (2013)]<br />
<br />
<br />
<br />
==Raw Block data (blk*.dat)==<br />
<br />
Block files store the raw blocks as they were received over the network. <br />
<br />
Block files are about 128 MB, allocated in 16 MB chunks to prevent excessive fragmentation. As of October 2015, the block chain is stored in about 365 block files, for a total of about 45 GB. <br />
<br />
Each block file (blk1234.dat) has a corresponding undo file (rev1234.dat) which contains the data necessary to remove blocks from the blockchain in the event of a reorganization (fork). <br />
<br />
Info about the block files is stored in the block index (the LevelDB) in two places: <br />
* General info about the files themselves is held in the "f" records in the block index LevelDB (meaning keys "fxxxx", where "xxxx" is the 4 digit file number), including: <br />
** Number of blocks stored in the file<br />
** File size (and the corresponding undo file size) <br />
** Lowest and highest block in the file<br />
** Timestamps - earlier and latest blocks in the file<br />
<br />
* Info about where to find a particular block on disk is in the "b" ("b" = block) record: <br />
** Each block contains a pointer to the block is on disk (a file number and an offset)<br />
<br />
<br />
'''Accessing the block data files from the code'''<br />
<br />
The block files are accessed through: <br />
<br />
1) DiskBlockPos: a struct that is simply a pointer to a block's location on disk (a file number and an offset.) <br />
<br />
2) ''vInfoBlockFiles'': a vector of BlockFileInfo objects. This variable is used to perform such tasks as: <br />
* Determine whether new blocks can fit into the current file or a new file needs to be created<br />
* Calculate the total disk usage by block & undo files <br />
* Iterate through the block files and find ones that can be pruned<br />
<br />
Blocks are written to disk as soon as they are received, in AcceptBlock. (The actual disk write operation is in WriteBlockToDisk [<u>main.cpp:1164</u>]). Note that there is some overlap of the code that accesses block files with the code that accesses and writes to the coins database (/chainstate). There is a complex system of when to flush state to disk. None of this code affects block files, which are simply written to disk when received. Once they have been received and stored, the block files are only needed for serving blocks to other nodes. <br />
<br />
<br />
<br />
'''More info about block files'''<br />
<br />
See here: [https://github.com/sipa/bitcoin/commit/5382bcf8cd23c36a435c29080770a79b5e28af42 the commit that puts multiple blocks in a block file (2012)]<br />
<br />
==Block index (leveldb)==<br />
<br />
The block index holds metadata about all known blocks, including where the block is stored on disk. <br />
<br />
Note that the set of "known blocks" is a superset of the longest chain, because it includes blocks that were received and processed but are not part of the active chain - for example, orphaned blocks that were detached from the active chain in a small reorganization. <br />
<br />
'''Terminology'''<br />
<br />
The terminology can be a little confusing here, because while people normally think of the "blockchain" as being synonymous with the active chain (an uninterrupted, linear chain of X blocks starting with the genesis block and continuing to the current tip), there are some places in the code where "blockchain" refers to the active chain plus the numerous, mostly short forks off the chain that our node happens to know about. <br />
<br />
a) Block Tree<br />
<br />
A better term for the set of known blocks stored on disk is "block tree," as this term contemplates a tree structure with numerous branches (albeit small ones) from the main chain. Indeed, the block index LevelDB is accessed through the "CBlockTreeDB" wrapper class, defined in <u>src/txdb.h</u>. Note that it's perfectly fine, indeed it is expected, that different nodes would have slightly different block trees; what matters is that they agree on the active chain.<br />
<br />
'''Key-value pairs'''<br />
<br />
Inside the actual LevelDB, the used key/value pairs are:<br />
<br />
'b' + 32-byte block hash -> block index record. Each record stores:<br />
* The block header<br />
* The height.<br />
* The number of transactions.<br />
* To what extent this block is validated.<br />
* In which file, and where in that file, the block data is stored.<br />
* In which file, and where in that file, the undo data is stored.<br />
<br />
'f' + 4-byte file number -> file information record. Each record stores:<br />
* The number of blocks stored in the block file with that number.<br />
* The size of the block file with that number ($DATADIR/blocks/blkNNNNN.dat).<br />
* The size of the undo file with that number ($DATADIR/blocks/revNNNNN.dat).<br />
* The lowest and highest height of blocks stored in the block file with that number.<br />
* The lowest and highest timestamp of blocks stored in the block file with that number.<br />
<br />
'l' -> 4-byte file number: the last block file number used.<br />
<br />
'R' -> 1-byte boolean ('1' if true): whether we're in the process of reindexing.<br />
<br />
'F' + 1-byte flag name length + flag name string -> 1 byte boolean ('1' if true, '0' if false): various flags that can be on or off. Currently defined flags include:<br />
* 'txindex': Whether the transaction index is enabled.<br />
<br />
't' + 32-byte transaction hash -> transaction index record. These are optional and only exist if 'txindex' is enabled (see above). Each record stores:<br />
* Which block file number the transaction is stored in.<br />
* Which offset into that file the block the transaction is part of is stored at.<br />
* The offset from the start of that block to the position where that transaction itself is stored.<br />
<br />
<br />
See here: [http://bitcoin.stackexchange.com/questions/28168/what-are-the-keys-used-in-the-blockchain-leveldb-ie-what-are-the-keyvalue-pair StackExchange post by Pieter Wuille (2014)]<br />
<br />
<br />
'''Data Access Layer'''<br />
<br />
The database is accessed through CBlockTreeDB wrapper class. See <u>txdb.h</u>. <br />
<br />
The wrapper is instantiated in a global variable called pblocktree, defined in <u>main.cpp.</u><br />
<br />
''CBlockIndex''<br />
<br />
Blocks stored in the database are represented in memory as CBlockIndex objects. An object of this type is first created after the ''header'' is received; the code does not wait to receive the full block. When headers are received over the network, they are streamed into a vector of CBlockHeaders, which are then checked. Each header that checks out causes a new CBlockIndex to be created, which is stored to the database. <br />
<br />
''CBlock / CBlockHeader''<br />
<br />
Note that these objects have little to do with the /blocks LevelDB. A CBlock holds the full set of transactions in the block, the data for which is stored in two places - in full, in raw format, in the blk???.dat files, and in pruned format in the [[UTXO]] database. The block index database cares not for such details, since it holds only the metadata for the block. <br />
<br />
''Loading the block database into memory''<br />
<br />
The entire database is loaded into memory on startup. See LoadBlockIndexGuts (<u>txdb.cpp</u>). This only takes a few seconds. <br />
<br />
The blocks ('b' keys) are loaded into the global "mapBlockIndex" variable. "mapBlockIndex" is an unordered_map that holds CBlockIndex for each block in the entire block tree; not just the active chain. <br />
<br />
mapBlockIndex is described in more detail in Chapter 6 - The Blockchain. <br />
<br />
The block file metadata ('f' keys) is loaded into vInfoBlockFiles.<br />
<br />
==The UTXO set (chainstate leveldb)==<br />
<br />
The UTXO database was introduced in 2012 in [https://github.com/bitcoin/bitcoin/pull/1677 pull request #1677 - "Ultraprune."]<br />
<br />
The idea behind "Ultraprune" is to reduce the size of (prune) the set of past transactions, keeping only those parts of past transactions that are necessary to validate later transactions. <br />
<br />
Say you have a transaction T1 which takes two inputs and sends to 3 outputs: O1,O2,O3. Two of those outputs (O1, O2) have been used as inputs in a later transaction, T2. Once T2 has been mined, T1 only has one item of interest (O3). There's no reason to keep T1 around in its entirety. Instead, a slimmed-down version of T1 will suffice, consisting only of O3 (locking script and amount) and certain basic information about T1 (height, whether it is a coinbase, etc.)<br />
<br />
The description of ultraprune is on the specific "ultraprune" commit within the pull: <br />
<br />
: -------------<br />
<br />
: This switches bitcoin's transaction/block verification logic to use a "coin database", which contains all unredeemed transaction output scripts, amounts and heights.<br />
<br />
: The name ultraprune comes from the fact that instead of a full transaction index, we only (need to) keep an index with unspent outputs. For now, the blocks themselves are kept as usual, although they are only necessary for serving, rescanning and reorganizing.<br />
<br />
: The basic data structures are CCoins (representing the coins of a single transaction), and CCoinsView (representing a state of the coins database). There are several implementations for CCoinsView. A dummy, one backed by the coins database (coins.dat), one backed by the memory pool, and one that adds a cache on top of it. FetchInputs, ConnectInputs, ConnectBlock, DisconnectBlock, ... now operate on a generic CCoinsView.<br />
<br />
: The block switching logic now builds a single cached CCoinsView with changes to be committed to the database before any changes are made. This means no uncommitted changes are ever read from the database, and should ease the transition to another database layer which does not support transactions (but does support atomic writes), like LevelDB.<br />
<br />
: For the getrawtransaction() RPC call, access to a txid-to-disk index would be preferable. As this index is not necessary or even useful for any other part of the implementation, it is not provided. Instead, getrawtransaction() uses the coin database to find the block height, and then scans that block to find the requested transaction. This is slow, but should suffice for debug purposes.<br />
<br />
: -----------------<br />
<br />
<br />
See: [https://github.com/sipa/bitcoin/commit/450cbb0944cd20a06ce806e6679a1f4c83c50db2 Ultraprune - July 2012]<br />
<br />
'''Terminology'''<br />
<br />
"UTXO (Unspent Transaction Out):" An output from a transaction. This is colloquially referred to as a "coin." For this reason, the UTXO db is sometimes referred to as the "coins database."<br />
<br />
"UTXO set / coins database / chainstate database:" These terms are more or less synonymous and are used interchangeably. <br />
<br />
"Provably Unspendable:" A coin is provably unspendable if its scriptPubKey cannot be satisfied - for example, an OP_RETURN. A provably unspendable coin can be eliminated from the utxo database regardless of its amount. <br />
<br />
<br />
'''Key-value pairs'''<br />
<br />
The records in the chainstate levelDB are: <br />
<br />
'C' + 32-byte transaction hash -> unspent transaction output record for that transaction. These records are only present for transactions that have at least one unspent output left. Each record stores:<br />
* The version of the transaction.<br />
* Whether the transaction was a coinbase or not.<br />
* Which height block contains the transaction.<br />
* Which outputs of that transaction are unspent.<br />
* The scriptPubKey and amount for those unspent outputs.<br><br><br />
'B' -> 32-byte block hash: the block hash up to which the database represents the unspent transaction outputs.<br />
<br />
See here: [http://bitcoin.stackexchange.com/questions/28168/what-are-the-keys-used-in-the-blockchain-leveldb-ie-what-are-the-keyvalue-pair StackExchange post by Pieter Wuille (2014)]<br />
<br />
'''Data Access Layer and Caching'''<br />
<br />
Access to the UTXO database is considerably more complex than the block index. This is because its performance is critical to the overall performance of the Bitcoin system. The block index is not so critical to performance because there are only a few hundred thousand blocks and a node running on decent hardware can retrieve and scroll through them in a few seconds (and does not need to do so very often.) On the other hand, there are millions of coins in the UTXO database and they must be checked and modified for each input of each transaction going into the mempool or included in a block. <br />
<br />
As sipa said in the ultraprune commit: <br />
: The basic data structures are CCoins (representing the coins of a single transaction), and CCoinsView (representing a state of the coins database). There are several implementations for CCoinsView. A dummy, one backed by the coins database (coins.dat), one backed by the memory pool, and one that adds a cache on top of it.<br />
<br />
This is not stated as clearly as it might have been, however; at least, not for the current state of the code. <br />
<br />
In 0.11, the instantiations of the CoinsView are: <br />
* dummy<br />
* database<br />
* pCoinsTip (a cache backed by the database)<br />
* "validation cache" (used when backed by pCoinsTip, in use when connecting a block) <br />
<br />
Separate from that chain of caches is the memory pool's CoinsView, which is backed by the database. <br />
<br />
<br />
The <i>class diagram</i> (data types) for the views is: <br />
<br />
CCoinsView (abstract class)<br />
/ \<br />
ViewDB ViewBacked <br />
(database) / \<br />
ViewMempool ViewCache<br />
<br />
<br />
Each class has one key characteristic: <br />
* View is the base class, declaring methods for verifying that coins exist (HaveCoins), retrieving coins (GetCoins), etc. <br />
* ViewDB has code to interact with the LevelDB. <br />
* ViewBacked has a pointer to another View; thus it is "backed" by another view (version) of the UTXO set. <br />
* ViewCache has a cache (a map of CCoins). <br />
* ViewMempool associates a mempool with a view. <br />
<br />
<br />
<br />
Those are the defined classes; whereas the <i>object diagram</i> is: <br />
<br />
<br />
Database <br />
/ \<br />
MemPool Blockchain cache (pcoinsTip) <br />
View/Cache \<br />
Validation cache<br />
<br />
<br />
<br />
Here is a table summarizing the instantiations of Views: <br />
<br />
{| class="wikitable"<br />
|-<br />
! Object !! Type !! Backed By? !! Description / Purpose<br />
|-<br />
| DB view || ViewDB || n/a || Represents the UTXO set according to the /chainstate LevelDB. Retrieves coins and flushes changes to the LevelDB.<br>Creation in code (instantiation): see <u>init.cpp:1131</u><br />
|-<br />
| pCoinsTip<br>(blockchain cache) || ViewCache || DB view || Holds the UTXO set corresponding to the active chain's tip. Retrieves/flushes to the database view.<br>Creation in code: see <u>init.cpp:1133</u><br />
|-<br />
| Validation cache || ViewCache || pCoinsTip || This cache's lifetime is within ConnectTip (or DisconnectTip).<br>Its purpose is to keep track of modifications to the UTXO set while processing a block.<br>If the block validates, the cache is flushed to pcoinsTip.<br>If the block fails, the cache is discarded. <br>Creation in code: see <u>main.cpp:2231</u>: CCoinsViewCache view(pcoinsTip);<br />
|-<br />
| Mempool view || ViewMemPool || pCoinsTip || This object brings the mempool into view, meaning it can see both a UTXO set and the mempool.<br>Its purpose is to enable validation of chains of transactions, a.k.a. "zero-confirmation" transactions. (If chains of transactions weren't permitted, the mempool could simply validate against pcoinsTip.)<br>Thus, when queried, it can check if a given input can be found either in the mempool (i.e., "zero-conf") or in the blockchain's utxo set ("confirmed.")<br>Note that this object is not a cache; rather, it is a view that is used by the object below, which does contain a cache. <br>Creation in code: Its lifetime is that of AcceptToMemoryPool in <u>main.cpp</u>.<br />
|-<br />
| Mempool cache || ViewCache || Mempool view || The cache for the mempool. It contains a cache and sets its backend to be the mempool view.<br>Creation in code: Its lifetime is also that of AcceptToMemoryPool in <u>main.cpp</u>. <br />
|}<br />
<br />
<br />
''Loading the UTXO set''<br />
<br />
Access to the coins database is initialized in <u>init.cpp</u>: 1131-1133: <br />
<br />
pcoinsdbview = new CCoinsViewDB(nCoinDBCache, false, fReindex);<br />
pcoinscatcher = new CCoinsViewErrorCatcher(pcoinsdbview);<br />
pcoinsTip = new CCoinsViewCache(pcoinscatcher);<br />
<br />
The code starts by initializing a CoinsViewDB, which is equipped with methods to load coins from the LevelDB. <br><br />
The error catcher is a little hack that can be ignored. <br><br />
Next, the code initalizes pCoinsTip, which is the cache representing the state of the active chain, and is backed by the database view. <br><br />
<br />
<br />
''Cache vs. Database''<br />
<br />
The FetchCoins function in coins.cpp demonstrates how the code uses the cache vs. the database: <br />
1 CCoinsMap::iterator it = cacheCoins.find(txid);<br />
2 if (it != cacheCoins.end())<br />
3 return it;<br />
4 CCoins tmp;<br />
5 if (!base->GetCoins(txid, tmp))<br />
6 return cacheCoins.end();<br />
7 CCoinsMap::iterator ret = cacheCoins.insert(std::make_pair(txid, CCoinsCacheEntry())).first;<br />
<br />
First, the code searches the cache for the coins for a given transaction id. (line 1)<br><br />
If found, it returns the "fetched" coins. (lines 2-3) <br><br />
If not, it searches the database. (line 5) <br><br />
If found in the database, it updates the cache. (line 7) <br><br />
<br><br />
Note: if the cache's backend is another cache, then the term "database" really means "parent cache." <br />
<br><br />
<br><br />
<br />
''Flushing the Validation Cache to the Blockchain Cache'' <br />
<br />
The validation cache is flushed to the blockchain cache after connecting a block, just before it goes out of scope. The scope is captured in ConnectTip, and specifically, in the code block <u>main.cpp</u>:2231-2243. In that code block, there is a call to ConnectBlock, during which the code stores the new coins in the validation cache. (Specifically, see UpdateCoins() in <u>main.cpp</u>.) At the end of the code block, the validation cache is flushed. Since its "parent view" is also a cache (pcoinsTip, the "blockchain cache") the code will call the parent's ViewCache::BatchWrite, which swaps the updated coin entries into its own cache. (Polymorphism in action: Later, when the the blockchain cache flushes to the database view, the code will run CoinsViewDB::BatchWrite, the last line of which writes to the LevelDB.) <br />
<br />
In summary, usage of the validation cache is straightforward: it is instantiated, used, flushed, and goes out of scope in the aforementioned code block. <br />
<br />
<br />
''Flushing the Blockchain Cache to the Database'' <br />
<br />
Flushing the validate cache was simple because the code only shuffled items between two caches in memory (of which no one is aware outside of the caching code.) Flushing the blockchain cache to the database is a bit more complicated. At the lowest level, the mechanics of flushing the blockchain cache (pcoinsTip) is the same as the validation cache: the Flush() method calls BatchWrite on its backend (the "base" pointer), and in this case that means BatchWrite on the database view. Up a level, Flush() is called from FlushStateToDisk (FSTD) - <u>main.cpp</u>:2098. FlushStateToDisk is invoked at a few different points, with a given ''mode'': <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! Flush Mode !! Description !! When called<br />
|-<br />
| IF_NEEDED || Flush only if the cache is over its size limit. || Right after connecting (or disconnecting) a block and flushing the validation cache.<br>See ConnectTip / DisconnectTip.<br />
|-<br />
| ALWAYS || Flush cache. || During initialization only. <br />
|-<br />
| PERIODIC || Here, the code considers other data points to decide whether to flush.<br>Is the code ''almost'' over its size limit?<br>Has it been a long time since the cache was flushed?<br>If so, then proceed.|| At end of ActivateBestChain()<br>(Code comment: "write changes periodically to disk, after relay"). <br />
|}<br />
<br />
<br />
The idea is to flush the block cache frequently (to avoid having to download a large number of blocks if the program crashes), but the coins cache infrequently (in order to maximize the benefit from the coins cache.) <br />
<br />
Specifically, the block cache is guaranteed to be flushed once an hour, whereas the coins cache once per day. (See here: [https://github.com/bitcoin/bitcoin/pull/6102#issuecomment-98847663 Sipa comment on PR 6102])<br />
<br />
The FlushStateToDisk code is well-commented so for more info, the curious reader can check <u>main.cpp</u>.<br />
<br />
==Raw undo data (rev*.dat)==<br />
<br />
The undo data contains the information that is necessary to disconnect or "roll back" a block: specifically, the coins that were spent by the block in question.<br />
<br />
So, the data being written is essentially a set of CTxOut objects. (A CTxOut is simply an amount and a script - see <u>primitives/transaction.h</u>:107-108).<br />
<br />
The matter is complicated slightly by the fact that if the coin is the last one being spent by its transaction, the undo data needs to store the transaction's metadata (the txn's block height, whether it's a coinbase, and its version.) So, if you have a transaction T with outputs O1,O2,O3 spent in that order, for O1 and O2 all that will be written to the undo file is the amount and the script. For 03, the undo file will have the amount, the script, plus T's height and version, and whether T is a coinbase.<br />
<br />
The undo data is written to the raw file with the following code: <br />
fileout << blockundo; (main.cpp:1567 [UndoWriteToDisk])<br />
<br />
This line of code calls the serialization function on the CBlockUndo - which is basically just a vector of coins (CTxOuts.) Finally, a checksum is written to the undo file. The checksum is used during initialization to verify that any undo data being checked is intact. See [https://github.com/bitcoin/bitcoin/pull/2145 Pull 2145]<br />
<br />
The undo data is used when disconnecting a block. The DisconnectBlock() code is discussed further down this wiki page in The Blockchain: Reorganizations.<br />
<br />
==Use of LevelDB==<br />
<br />
LevelDB is a key-value store that was introduced to store the block index and UTXO set (chainstate) in 2012 as part of the complex "Ultraprune" pull (PR 1677). See here: [https://github.com/bitcoin/bitcoin/pull/1677/commits the 27 commits on Ultraprune]. <br />
<br />
On the subject of why LevelDB is used, core developer Greg Maxwell stated the following to the [http://bitcoin-development.narkive.com/XAPoxKZU/patch-switching-bitcoin-core-to-sqlite-db bitcoin-dev mailing list in October 2015]: <br />
<br />
:: I think people are falling into a trap of thinking "It's a <database>, I know a <black box> for that!"; but the application and needs are very specialized here. . . It just so happens that on the back of the very bitcoin specific cryptographic consensus algorithim there was a slot where a pre-existing high performance key-value store fit; and so we're using one and saving ourselves some effort... <br />
<br />
One might ask whether different nodes could use different databases - as long as they retrieve the same data, what's the difference? The issue here is "bug-for-bug compatibility" - if one database has a bug that causes records to not be returned under certain circumstances, then all other nodes bst have the same bug, else the network could fork as a result. <br />
<br />
Greg Maxwell stated the following in [http://bitcoin-development.narkive.com/XAPoxKZU/patch-switching-bitcoin-core-to-sqlite-db the same thread referenced above (in response to a proposal to switch to using sqlite)]: <br />
<br />
:: ...[D]atabases sometimes have errors which cause them to fail to return records, or to return stale data. And if those exist consistency must be maintained; and "fixing" the bug can cause a divergence in consensus state that could open users up to theft.<br />
<br />
:: Case in point, prior to leveldb's use in Bitcoin Core it had a bug that, under rare conditions, could cause it to consistently return not found on records that were really there. . . Leveldb fixed this serious bug in a minor update. But deploying a fix like this in an uncontrolled manner in the bitcoin network would potentially cause a fork in the consensus state; so any such fix would need to be rolled out in an orderly manner.<br />
<br />
==See also==<br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_1):_Overview Bitcoin Core 0.11 (Ch 1): Overview]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_3):_Initialization_and_Startup Bitcoin Core 0.11 (Ch 3): Initialization and Startup]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_4):_P2P_Network Bitcoin Core 0.11 (Ch 4): P2P Network]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_5):_Initial_Block_Download Bitcoin Core 0.11 (Ch 5): Initial Block Download]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_6):_The_Blockchain Bitcoin Core 0.11 (Ch 6): The Blockchain]<br />
<br />
<br />
[[Category:Technical]]<br />
[[Category:Developer]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Bitcoin_Core_0.11_(ch_3):_Initialization_and_Startup&diff=68024Bitcoin Core 0.11 (ch 3): Initialization and Startup2020-06-27T12:54:12Z<p>Furunodo: /* Initialization steps (init.cpp) */</p>
<hr />
<div><br />
This page describes the Bitcoin Core code that manages startup and initialization. <br />
<br />
==Program entry point== <br />
<br />
The program's entry point can be found in <u>bitcoind.cpp</u>.<br />
<br />
main() is three lines of code:<br />
* SetupEnvironment() (all this does is set the program's locale)<br />
* Connect signal handlers<br />
* AppInit() (this function loops for the life of the program)<br />
<br />
<br />
AppInit: this is located nearby in <u>bitcoind.cpp</u>: <br />
* Parses the command line<br />
* Opens the data directory<br />
* Reads the config file<br />
* Forks a process (if running as a daemon)<br />
* Passes control to AppInit2(), found in <u>init.cpp</u>.<br />
<br />
<br />
==Initialization steps (<u>init.cpp</u>)==<br />
<br />
AppInit2() initializes the bitcoin system. <br />
<br />
It contains about 800 lines of code, which are broken into 12 steps. <br />
<br />
Where each step begins is documented in the code. <u>Init.cpp</u> has a few functions at the top of the file, but for the most part it consists of AppInit2(). <br />
<br />
The following table summarizes the steps: <br />
<br />
{| class="wikitable"<br />
|-<br />
! Initialization<br>Step !! Short Description !! Longer Description<br />
|-<br />
| 1 || OS-specific setup tasks || These tasks are not particularly interesting.<br>For more info, see the code. <br />
|-<br />
| 2 || Parameter Interactions || Certain command-line options require other options to be set in a certain way.<br>For example, -zapwallettxes implies a -rescan, thus the code will set the -rescan flag=true if it isn't already. <br />
|-<br />
| 3 || Internal flags / <br>Parameter sanity-check || Sets global variables for certain parameters.<br>For the wallet, it sanity-checks transaction fee levels (makes sure your fee is high enough to qualify for relay [error]; but not absurdly high [warning]). <br />
|-<br />
| 4 || Application init. / RPC Server || <br />
Locks the data directory. (If unable, print error and quit.)<br><br />
Spawn X threads for the Script-checking engine. (Default=0, meaning use all available processors; boost::thread::hardware_concurrency).<br><br />
Start RPC server in "warmup" mode. <br />
|-<br />
| 5 || Verify wallet database integrity || If wallet is enabled, try to open it.<br><br />
If the user knows that the wallet has been corrupted (-salvagewallet), try to recover the private keys. <br />
|-<br />
| 6 || Network Initialization || <br />
The node registers for certain signals.<br><br />
Checks whether the user wants to interact only with peers on a certain network (ip4, ip6, tor).<br><br />
Checks whether to use onion routing (tor).<br><br />
Checks whether the user wants to whitelist any specific peers.<br><br />
Attempts to listen on the bitcoin port (exits on failure).<br><br />
If user specified a certain peer to seed connections, attempt to connect. <br />
|-<br />
| 7 || Load the block chain. || <br />
Load the blockchain into memory and initialize the [[UTXO]] caches.<br><br />
<br><br />
<u>Calculate cache sizes.</u><br><br />
There is a total cache size, which is divided amongst three specific caches.<br> <br />
Default total cache size = 100MB (Max: 4 GB, min: 4 MB).<br> <br />
1) Blockchain cache: 1/8 of the total cache, but shouldn't be larger than 2MB.<br><br />
2) UTXO database cache : 25-50% of the remaining cache space. This is the LevelDB cache.<br><br />
This stores uncompressed blocks of LevelDB data and is managed by LevelDB, as described in [http://leveldb.googlecode.com/git-history/1.17/doc/index.html the LevelDB documentation.]<br><br />
3) UTXO in-memory cache: Half of the remaining cache space.<br><br />
This cache size defines the size of the cacheCoins object (a protected member of CoinsViewCache).<br><br />
TODO: verify that this statement is correct... <br><br />
<br><br />
<u>Load the blockchain into mapBlockIndex.</u><br><br />
By "blockchain" this means the entire block tree (all known blocks, not just those in the active chain.)<br><br />
What is loaded into memory are the CBlockIndex objects, which contain metadata about the block. <br><br />
Verifies the last 288 blocks (VerifyDB).<br><br />
Note: The program takes less than 1 second from startup until this point; this step takes about 10-20 seconds.<br><br />
<br><br />
<u>The UTXO set.</u><br><br />
The UTXO set is not loaded into memory; instead, the cache will be filled as coins are accessed from the database.<br><br />
Note that as of May 2015, storing the entire UTXO set in memory would require about 3.6 GB.<br><br />
As of Jan. 2016, the compressed data on disk is about 1.2 GB. <br />
|-<br />
| 8 || Load the wallet. || If this is the first time the program has been run, it creates a wallet and gives you an initial key (address).<br />
|-<br />
| 9 || Datadir maintenance || If the user is block-pruning, unset NODE_NETWORK and call the pruning function.<br />
|-<br />
| 10 || Import blocks || Scan for better chains in the block chain database, that are not yet connected as the active best chain.<br />
|-<br />
| 11 || Start node /<br>RPC server || <br />
Calls StartNode in net.cpp.<br><br />
This starts up the networking thread group, including ThreadProcessMessage, which is the program's main thread (see below). <br><br />
Transition RPC server from "warmup" mode to normal mode.<br />
|-<br />
| 12 || Finished<br />
|}<br />
<br />
<br />
When AppInit2 finishes, control returns to AppInit() in <u>bitcoind.cpp</u>.<br />
<br />
There, the code's top-level thread loops indefinitely in a function called WaitForShutdown(). It sleeps for 2 seconds and checks to see if the user pressed ctrl-C. If so, it calls Shutdown() back in <u>init.cpp</u>.<br />
<br />
Shutdown() shuts down the RPC server, stops the node, unregisters the signal handlers, etc., and then the program completes.<br />
<br />
==Cache Sizes==<br />
<br />
Step 7 initialized the cache sizes. There are 3 caches contemplated in step 7. Two are LevelDB database caches and the other is the coins cache, whose size is managed by the flushing code in <u>main.cpp</u>. <br />
<br />
The user can allocate a total cache size with -dbcache. The user cannot pick and choose how much space to allocate to each specific cache. The default total cache size = 100MB (Max: 4 GB, min: 4 MB). <br />
<br />
'''1) Block index cache'''<br />
<br />
This cache stores uncompressed chunks of the /blocks/index LevelDB data and is managed by LevelDB, as described in [https://web.archive.org/web/20160417094316/http://leveldb.googlecode.com/git-history/1.17/doc/index.html the LevelDB documentation.]<br><br />
<br />
If the user enables a full transaction index (-txindex=1) it can be up to 1/8 of the total cache size. If -txindex is not enabled then only 2 MiB is needed. <br />
<br />
<br />
'''2) UTXO database cache'''<br />
<br />
This is the LevelDB cache for the /chainstate database. <br />
<br />
This cache is allocated 25-50% of the remaining cache space, depending on the total cache size. <br />
<br />
<br />
'''3) UTXO in-memory cache'''<br />
<br />
This is the coins cache that is managed by the <u>main.cpp</u> code. (see FlushStateToDisk and related functions) <br />
<br />
The variable (nCoinsCache) is declared as extern in <u>main.h</u>. In <u>main.cpp</u>, it is hard-coded to 5000 * 300 (in-memory coins are about 300 bytes, so this means 5000 coins), however it should be re-initialized in Step 7. <br />
<br />
This cache is given all of the remaining cache space. <br />
<br />
This cache is not loaded during initialization, rather it is filled as coins are accessed. (This can be verified by the CCoinsViewCache constructor, which sets cachedCoinsUsage=0.)<br />
<br />
==Thread Startup==<br />
<br />
The code uses boost::thread_groups to manage the various threads.<br />
<br />
It should be noted that although Bitcoin Core is a multi-threaded program, "the reference Satoshi client is largely single-threaded." [https://github.com/bitcoin/bips/blob/master/bip-0031.mediawiki Comment by Mike Hearn in BIP 31 (2012)]<br />
<br />
What is meant is that the vast majority of the program's activity takes place in the messaging thread (ThreadMessageHandler - see below.) <br />
<br />
Almost all of the threads are part of a single, master thread group that is created on the stack at program startup (see <u>bitcoind.cpp</u>). This thread group is passed to <u>init.cpp</u> which creates a few child threads (including a number of script-checking threads, but these are all part of the master thread group, not a separate group.)<br />
<br />
The thread group is passed to <u>net.cpp</u>, which creates the networking threads, including the message-processing thread. <br />
<br />
The two other thread groups are task-specific: <br />
* rpc server thread group (see <u>rpcserver.h/cpp</u>)<br />
* miner thread group<br />
<br />
Naturally, the node will only create the RPC server thread group if the RPC server is activated, and will only create the miner thread group if it is mining. If both are disabled, then Bitcoin Core only has a single thread group. <br />
<br />
'''Child Threads'''<br />
<br />
The parent thread (meaning the thread in which the program begins operating) delegates almost all of the program's work to child threads. After spawning threads in <u>init.cpp</u> and <u>net.cpp</u>, the parent thread simply listens for a shutdown command, at which time the parent thread needs only to interrupt the threads in its thread group and proceed with shutdown. <br />
<br />
The child threads are summarized in this table, listed in the order in which they are created: <br />
<br />
<br />
{| class="wikitable"<br />
|-<br />
! Thread !! When / Where Created !! Description<br />
|-<br />
| Script-checking || Step 4<br>init.cpp || This is a set of threads - 4 by default.<br>Script-checking (including signature checking) is expensive so is handled in separate threads.<br />
|-<br />
| Scheduler || Step 4<br>init.cpp || Scheduler thread.<br> (TODO: describe)<br />
|-<br />
| RPC Threads || Step 4<br>rpcserver.cpp || If RPC server enabled, start a group of threads to handle RPC calls. <br />
|-<br />
| Import || Step 10<br>init.cpp || Imports blocks. Three scenarios:<br>1) Reindex (rescan all known blocks from blk???.dat files).<br>2) Bootstrap (use bootstrap.dat as an alternative to full IBD from the network.)<br>3) -loadblock (scan a specific blk???.dat file)<br>If none of those apply, this thread does nothing.<br />
|-<br />
| DNSAddressSeed || Step 11<br>net.cpp || Attempts to build a vector of IP addresses based on the dns seeds, stores the vector and the thread exits.<br>In a test in June 2014, this took about 4 seconds and found 158 addresses. <br />
|-<br />
| Plug & Play || Step 11<br>net.cpp || UPNP (Universal Plug & Play) <br>Deals with port mapping for UPNP.<br />
|-<br />
| SocketHandler || Step 11<br>net.cpp || <u>This thread services the sockets:</u><br>Waits for I/O on all the relevant sockets with a 50ms timeout.<br>Processes new incoming connections on listening socket and creates a CNode for the new peer.<br>Receives and sends data streams.<br>Sets sockets that have not done anything to a disconnected state.<br />
|-<br />
| OpenAddedConnections || Step 11<br>net.cpp || Initiates outbound connections specified by the user with the –addnode parameter.<br>If can't connect, sleeps for 2 minutes each cycle.<br />
|-<br />
| OpenConnections || Step 11<br>net.cpp || Initiates other outbound connections from DNS seeds (if that fails, find nodes based on fixed seeds)<br>If can't connect, sleeps for 500 milliseconds each cycle.<br />
|-<br />
| MessageHandler || Step 11<br>net.cpp || <u>This is the program's main thread.</u> <br> This thread runs a while(true) loop, receiving and sending messages. (See <u>net.cpp</u>:1049) <br>The code uses boost::signals2 to call the ProcessMessages and SendMessages functions in main.cpp.<br>(The code introducing signals is in PR 2154 - see the next-to-last commit in that pull.)<br>ProcessMessage and SendMessage run in this thread.<br>So, most of the code in <u>main.cpp</u> runs in this thread.<br />
|-<br />
| Wallet Flusher || Step 12<br>init.cpp || If wallet is enabled, this thread flushes the wallet periodically.<br />
|}<br />
<br />
<br />
<br />
==See also==<br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_1):_Overview Bitcoin Core 0.11 (Ch 1): Overview]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_2):_Data_Storage Bitcoin Core 0.11 (Ch 2): Data Storage]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_4):_P2P_Network Bitcoin Core 0.11 (Ch 4): P2P Network]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_5):_Initial_Block_Download Bitcoin Core 0.11 (Ch 5): Initial Block Download]<br />
<br><br />
[https://en.bitcoin.it/wiki/Bitcoin_Core_0.11_(ch_6):_The_Blockchain Bitcoin Core 0.11 (Ch 6): The Blockchain]<br />
<br />
<br />
[[Category:Technical]]<br />
[[Category:Developer]]</div>Furunodohttps://en.bitcoin.it/w/index.php?title=OP_RETURN&diff=68023OP RETURN2020-06-27T12:54:00Z<p>Furunodo: </p>
<hr />
<div>'''OP_RETURN''' is a [[script]] opcode used to mark a transaction output as invalid. Since any outputs with OP_RETURN are provably unspendable, OP_RETURN outputs can be used to [[Proof of burn|burn]] bitcoins.<br />
<br />
== Is storing data in the blockchain acceptable? ==<br />
Many members of the Bitcoin community believe that use of OP_RETURN is irresponsible in part because Bitcoin was intended to provide a record for financial transactions, not a record for arbitrary data. Additionally, it is trivially obvious that the demand for external, massively-replicated data store is essentially infinite. Despite this, OP_RETURN has the advantage of not creating bogus [[UTXO]] entries, compared to some other ways of storing data in the blockchain.<br />
<br />
From [https://bitcoin.org/en/release/v0.9.0#opreturn-and-data-in-the-block-chain Bitcoin Core release 0.9.0]:<br />
<blockquote><br />
This change is not an endorsement of storing data in the blockchain. The OP_RETURN change creates a provably-prunable output, to avoid data storage schemes – some of which were already deployed – that were storing arbitrary data such as images as forever-unspendable TX outputs, bloating bitcoin's UTXO database.<br />
<br />
Storing arbitrary data in the blockchain is still a bad idea; it is less costly and far more efficient to store non-currency data elsewhere.<br />
</blockquote><br />
<br />
== OP_RETURN applications ==<br />
OP_RETURN can be used for digital asset proof-of-ownership, and has at times been used to convey additional information needed to send transactions (see [[ECDH address]]).<br />
<br />
<br />
{{DISPLAYTITLE:OP_RETURN}}</div>Furunodohttps://en.bitcoin.it/w/index.php?title=Weaknesses&diff=68022Weaknesses2020-06-27T12:53:53Z<p>Furunodo: /* Illegal content in the block chain */</p>
<hr />
<div>== Might be a problem ==<br />
=== Wallet Vulnerable To Theft ===<br />
<br />
The [[wallet]] is stored unencrypted, by default, and thus becomes a valuable target for theft. Recent releases of the Bitcoin client now supports encryption to protect the wallet data, though the user must opt-in.<br />
<br />
==== New wallets vulnerable with old passwords via backups ====<br />
<br />
An old copy of a wallet with its old password is often easily retrievable via an existing backup facility (particularly Apple Time-Machine): draining that old wallet, with its old password, drains the current wallet with the current password -- this is contrary to most non-technical users expectation of what 'change the password on your wallet' should mean following password compromise.<br />
<br />
An initial solution is to mandate (either in code or as expressed policy) that changing a wallet's password causes (or asks the user to cause) the creation of a new wallet with new addresses, and the sending of existing sums to them. Backed-up copies of the original wallet with the original password would then be empty, should they be compromised. On the downside, the password-changing process would potentially take much longer, cost a transaction fee or more, and - intially at least - the new wallet is no longer backed up. On the upside, non-technical users won't find their wallets drained from security compromises they believed they had closed, nor be required to locate existing backups of a wallet in order to destroy them.<br />
<br />
=== Tracing a coin's history ===<br />
Tracing a coin's history can be used to connect identities to addresses (the [[Anonymity]] article elaborates on this concern in greater detail).<br />
<br />
=== Sybil attack ===<br />
If an attacker attempts to fill the network with clients that they control, you would then be very likely to connect only to attacker nodes. Although Bitcoin never uses a count of nodes for anything, completely isolating a node from the honest network can be helpful in the execution of other attacks.<br />
<br />
This state can be exploited in (at least) the following ways:<br />
<br />
* the attacker can refuse to relay blocks and transactions from everyone, effectively disconnecting you from the network<br />
* the attacker can relay only blocks that they create, effectively putting you on a separate network and then also leaving you open to [[double-spending]] attacks<br />
* if you rely on transactions with 0 confirmations, the attacker can just filter out certain transactions to execute [[double-spending]] attacks<br />
* low-latency encryption/anonymization of Bitcoin's transmissions (with Tor, JAP, etc.) can be defeated relatively easily with a timing attack if you're connected to several of the attacker's nodes and the attacker is watching your transmissions at your ISP<br />
<br />
Bitcoin makes these attacks more difficult by only making an outbound connection to one IP address per /16 (x.y.0.0). Incoming connections are unlimited and unregulated, but this is generally only a problem in the anonymity case where you're probably already unable to accept incoming connections.<br />
<br />
Looking for suspiciously-low network hash-rates may help prevent the second one.<br />
<br />
=== Packet sniffing ===<br />
Someone who can see all of your Internet traffic can easily see when you send a transaction that you didn't receive (which suggests you originated it). Bitcoin-QT has good Tor integration which closes this attack vector if used.<br />
<br />
=== Denial of Service (DoS) attacks ===<br />
Sending lots of data to a node may make it so busy it cannot process normal Bitcoin transactions. Bitcoin has some denial-of-service prevention built-in, but is likely still vulnerable to more sophisticated denial-of-service attacks.<br />
<br />
These are the current Bitcoin Satoshi client protections to deter DoS attacks, as of version 0.7.0:<br />
<br />
# Does not forward orphan transactions/blocks<br />
# Does not forward double-spend transactions<br />
# Does not forward the same block, transaction or alert twice to the same peer.<br />
# Continuous rate-limit of free transactions to mitigate 'penny-flooding'<br />
# Keeps a DoS score of each connected peer and disconnects from a peer that send messages that fail to comply with the rules.<br />
# Bans IP addresses that misbehave for a time lapse (24 hours default)<br />
# Limits the number of stored orphan transactions (10000 by default)<br />
# Uses a signature cache to prevent attacks that try to continuously trigger the re-verification of stored orphan transactions (protects from https://bitcointalk.org/index.php?topic=136422.0 attack)<br />
# Limits the number of stored signatures in the signature cache (50000 signatures by default)<br />
# Tries to catch all possible errors in transactions before the signature verifications take place, to avoid DoS attacks on CPU usage.<br />
# Penalizes peers that send lots of duplicate/expired/invalid-signature/whatever alerts, so they eventually get banned.<br />
# In orphan/signature caches, when removing an item, evicts a random entry.<br />
# Data structures are specially chosen to avoid loops in which the number of iterations can be controlled by an attacker that result in exponential complexity.<br />
# Ignores big orphan transactions, to avoid a send-big-orphans memory exhaustion attack.<br />
# In RPC: Only sends a HTTP 403 response if it's not using SSL to prevent a DoS during the SSL handshake.<br />
# In RPC: Sleeps some time if authorization fails to deter brute-forcing short passwords.<br />
# In GUI: Limits URI length to prevent a DoS against the QR-Code dialog<br />
# Considers non-standard signature scripts with size greater than 500 bytes.<br />
# Considers non-standard signature scripts that contain operations that are not PUSHs.<br />
# Does not forward nor process non-standard transactions<br />
<br />
These are protocol rules built to prevent DoS:<br />
<br />
# Restricts the block size to 1 megabyte.<br />
# Restricts the maximum number of signature checks a transaction input may request<br />
# Limits the size of each script (up to 10000 bytes)<br />
# Limits the size of each value pushed while evaluating a a script (up to 520 bytes)<br />
# Limits the number of expensive operations in a script (up to 201 operations). All but pushs are considered expensive. Also each key argument of signature checking in multi-signature checking (OP_CHECKMULTISIG) is considered an additional operation.<br />
# Limits the number of key arguments OP_CHECKMULTISIG can use (up to 20 keys)<br />
# Limits the number of the stack elements that can be stored simultaneously (up to 1000 elements, in standard and alt stacks together)<br />
# Limits the number of signature checks a block may request (up to 20000 checks)<br />
<br />
These are the Satoshi client protections added in version 0.8.0: <br />
<br />
# Transactions greater than 100 Kbytes are considered non-standard (protects from variations of the https://bitcointalk.org/index.php?topic=140078.0 attack).<br />
# Only the UXTO (Unspent Transaction Output Set) is stored in memory, the remaining data is stored on disk.<br />
# When processing a transaction, before fetching transaction inputs from disk to memory, the client checks that all the inputs are unspent (protects from the Continuous Hard Disk Seek/Read Activity (https://bitcointalk.org/index.php?topic=144122.0) DoS attack)<br />
<br />
<br />
Satoshi client does not directly limit peer bandwidth nor CPU usage.<br />
<br />
=== Forcing clock drift against a target node ===<br />
<br />
See [http://culubas.blogspot.com/2011/05/timejacking-bitcoin_802.html Timejacking] for a description of this attack. It can be fixed by changing how nodes calculate the current time.<br />
<br />
=== Illegal content in the block chain ===<br />
It is illegal in some countries to possess/distribute certain kinds of data. Since arbitrary data can be included in Bitcoin transactions, and full Bitcoin nodes must normally have a copy of all unspent transactions, this could cause legal problems. However, Local node policy generally doesn't permit arbitrary data (transactions attempting to embed data are non-standard), but steganographic embedding can still be used though this generally limits storage to small amounts. [http://sourceforge.net/mailarchive/message.php?msg_id=30705609 Various ideas have been proposed] to further limit data storage in the [[UTXO|UTXO set]] (but are not currently being seriously considered for deployment).<br />
<br />
=== Security Vulnerabilities and bugs ===<br />
It's possible but unlikely that a newly discovered bug or security vulnerability in the standard client could lead to a block chain split, or the need for every node to upgrade in a short time period. For example, a single malformed message tailored to exploit a specific vulnerability, when spread from node to node, could cause the whole network to shutdown in a few hours. Bugs that break user anonymity, on the contrary, have been found, since the pseudo-anonymity property of Bitcoin has been analyzed less.<br />
Starting from version 0.7.0, Bitcoin client can be considered a mature project. The security critical sections of the source code are updated less and less frequently and those parts have been reviewed by many computer security experts. Also Bitcoin Satoshi client has passed the test of being on-line for more than 3 years, without a single vulnerability being exploited ''in the wild''. <br />
See [[Common Vulnerabilities and Exposures]] for a detailed list of vulnerabilities detected and fixed.<br />
<br />
=== Energy Consumption ===<br />
Energy consumption for mining has a high correlation with bitcoin value (exchange rate). Because variable costs of [[mining]] are dominated by electricity price, the economic equilibrium for the mining rate is reached when global electricity costs for mining approximate the value of [[mining]] reward plus [[transaction_fee | transaction fees]]. <br />
<br />
So the higher the value of one bitcoin, the higher the value of mining rewards and transaction fees, the higher the energy consumption of the bitcoin network in the long run.<br />
<br />
* more efficient mining gear does not reduce energy use of the bitcoin network. It will only raise the network [[difficulty]]<br />
* cheaper energy linearly increases mining energy use of the bitcoin network<br />
* the same conclusions apply to all [[proof of work]] based currencies.<br />
<br />
== Probably not a problem ==<br />
<br />
===Breaking the cryptography===<br />
SHA-256 and [[ECDSA]] are considered very strong currently, but they might be broken in the far future. If that happens, Bitcoin can shift to a stronger algorithm. [https://bitcointalk.org/index.php?topic=191.msg1585#msg1585 More info].<br />
<br />
===Scalability===<br />
Bitcoin can easily scale beyond the level of traffic VISA sees globally today. See the discussion on the [[scalability]] page for more information.<br />
<br />
===Segmentation===<br />
If there is even a "trickle" of a connection between two sides of a segmented network, things should still work perfectly. When block chains are combined, all of the non-generation transactions in the shorter chain are re-added to the transaction pool -- they'll start over at 0/unconfirmed, but they'll still be valid. No mature transactions will be lost unless the segmentation persists for longer than ~120 blocks. Then generations will start to mature, and any transactions based on those generations will become invalid when recombined with the longer chain. [https://bitcointalk.org/index.php?topic=241.msg2071#msg2071 More info].<br />
<br />
=== Attacking all users ===<br />
The IP addresses of most users are totally public. You can use Tor to hide this, but the network won't work if everyone does this. Bitcoin requires that ''some'' country is still free.<br />
<br />
=== Dropping transactions ===<br />
Nodes that generate blocks can choose not to include a transaction in their blocks. When this happens, the transaction remains "active" and can be included in a later block. Two things discourage this:<br />
* Nodes only hash a fixed-size ''header'', so there is no speed advantage to dropping transactions.<br />
* [[Satoshi]] has [https://bitcointalk.org/index.php?topic=165.msg1595#msg1595 communicated] that he will write code to stop this kind of thing if it becomes a problem.<br />
<br />
=== Attacker has a lot of computing power ===<br />
An attacker that controls more than 50% of the network's computing power can, for the time that he is in control, exclude and modify the ordering of transactions. This allows him to:<br />
* Reverse transactions that he sends while he's in control. This has the potential to [[Double-spending#51.25_attack|double-spend transactions]] that previously had already been seen in the block chain, affecting all coins that share a history with the reversed transaction<br />
* Reverse confirmations for any transaction that had previously been seen in the block chain while he’s in control. <br />
* Prevent some or all transactions from gaining any confirmations<br />
* Prevent some or all other miners from mining any valid blocks<br />
The attacker ''can't'':<br />
* Reverse other people's transactions without their cooperation (unless their coin history has been affected by a double-spend)<br />
* Prevent transactions from being sent at all (they'll show as 0/unconfirmed)<br />
* Change the number of coins generated per block<br />
* Create coins out of thin air<br />
* Send coins that never belonged to him<br />
<br />
Note that the above limitations only apply to the perspective of Bitcoin as seen by [[full node]]s. Some lightweight nodes work by trusting miners absolutely; from the perspective of Bitcoin as seen by lightweight nodes, miners ''can'' steal BTC, etc. This is one of the reasons why lightweight nodes are less secure than full nodes.<br />
<br />
With less than 50%, the same kind of attacks are possible, but with less than 100% rate of success.<br />
For example, someone with only 40% of the network computing power can overcome a 6-deep confirmed transaction with a 50% success rate <ref>https://bitcoil.co.il/Doublespend.pdf</ref>.<br />
<br />
It's much more difficult to change historical blocks, and it becomes exponentially more difficult the further back you go. As above, changing historical blocks only allows you to exclude and change the ordering of transactions. If miners rewrite historical blocks too far back, then full nodes with pruning enabled will be unable to continue, and will shut down; the network situation would then probably need to be untangled manually (eg. by updating the software to reject this chain even though it is longer).<br />
<br />
Since this attack doesn't permit all that much power over the network, it is expected that rational miners will not attempt it. A profit-seeking miner should always gain more by just following the rules, and even someone trying to destroy the system might find other attacks more attractive. Probably the most likely scenario where this attack would be employed would be for a government to try to get control over Bitcoin by acquiring a majority of hashing power (either directly or by enforcing rules on private miners within its borders). Then this government could use the transaction-censorship power listed above to do things like:<br />
<br />
* Prevent any transactions spending "stolen" coins, effectively destroying those coins. If the coins clearly are stolen, then there is a risk that this action will be accepted by the Bitcoin community, but this would set a very damaging precedent. If it becomes possible for coins to be blacklisted in this way, then it is a slippery slope toward blacklisting of other "suspicious" coins.<br />
* Prevent all transactions from unknown people, so everyone has to register with the government in order to transact.<br />
<br />
The appropriate response to any long-term attack by miners is a [[hardfork]] to change the proof-of-work function. This fires all existing miners, and allows totally new ones to replace them.<br />
<br />
See also: [[Majority_attack]]<br />
<br />
=== Spamming transactions ===<br />
{{main|Flood attack}}<br />
It is easy to send transactions to yourself repeatedly. If these transactions fill blocks to the maximum size (1MB), other transactions would be delayed until the next block.<br />
<br />
This is made expensive by the [[transaction fee|fees]] that would be required after the 50KB of free transactions per block are exhausted. An attacker will eventually eliminate free transactions, but Bitcoin fees will always be low because raising fees above 0.01 BTC per KB would require spending transaction fees. An attacker will eventually run out of money. Even if an attacker wants to waste money, transactions are further prioritized by the time since the coins were last spent, so attacks spending the same coins repeatedly are less effective.<br />
<br />
=== The [[Double-spending#Finney_attack|Finney attack]] ===<br />
Named for Hal Finney, who first described this variation of a double-spend attack involving accepting [http://www.bitcointalk.org/index.php?topic=3441.msg48384#msg48384 0-confirmation transactions]. Accepting 0-confirmation large-value transactions is problematic; accepting them for low-value transactions (after waiting several seconds to detect an ordinary double-spend attempt) is probably safe.<br />
<br />
===Rival/malicious client code===<br />
Any rival client must follow Bitcoin's rules or else all current Bitcoin clients will ignore it. You'd have to actually get people to ''use'' your client. A better client that pretends to follow the same rules, but with an exception known only to the author (possibly by making it closed source), might conceivably be able to gain widespread adoption. At that point, its author could use his exception and go largely unnoticed.<br />
<br />
== Definitely not a problem ==<br />
<br />
===Coin destruction===<br />
Bitcoin has 2.1 quadrillion raw units, making up 8 decimals of BTC precision, so the entire network could potentially operate on much less than the full quantity of Bitcoins. If deflation gets to the point where transactions of more than 10 BTC are unheard of, clients can just switch to another unit so that, for example, it shows 10 mBTC rather than 0.01 BTC.<br />
<br />
The maximum number of raw units might not be enough if the ''entire world'' starts using BTC, but it would not be too difficult to increase precision in that case. The transaction format and version number would be scheduled to change at some particular block number after a year or two, and everyone would have to update by then.<br />
<br />
===Generating tons of addresses===<br />
Generating an address doesn't touch the network at all. You'd only be wasting your CPU resources and disk space.<br />
<br />
Also, a collision is highly unlikely.<br />
<br />
Keys are 256 bit in length and are hashed in a 160 bit address.(2^160th power)<br />
Divide it by the world population and you have about 215,000,000,000,000,000,000,000,000,000,000,000,000 addresses per capita.(2.15 x 10^38)[http://www.wolframalpha.com/input/?i=2^160+%2F+world+population]<br />
<br />
===Everyone calculates at the same rate===<br />
If everyone began with identical blocks and started their nonce at 1 and incremented, the fastest machine would always win. However, each block contains a new, random public key known only to you in the list of transactions. The 256-bit "Merkle tree" hash of this is part of the block header.<br />
<br />
So everyone begins with slightly different blocks and everyone truly has a random chance of winning (modified by CPU power).<br />
<br />
===Generate "valid" blocks with a lower difficulty than normal===<br />
Using unmodified Bitcoin code, an attacker could segment himself from the main network and generate a long block chain with a lower difficulty than the real network. These blocks would be totally valid for his network. However, it would be impossible to combine the two networks (and the "false" chain would be destroyed in the process).<br />
<br />
"Block chain length" is calculated from the combined difficulty of all the blocks, not just the number of blocks in the chain. The one that represents the most computation will win.<br />
<br />
==See Also==<br />
<br />
* [[Double-spending]]<br />
* [http://bitcoin.stackexchange.com/questions/10025/where-can-i-find-well-written-criticism-about-bitcoin Stack Exchange]<br />
<br />
[[Category:Technical]]</div>Furunodo