Bitcoin Wiki - User contributions [en]

Marchenko Ltd

2012-04-04T10:12:46Z

Wcoenen: repaired link which should point to bitcointalk.org, not bitcoin.org

Sells contracts for purchasing mining rig capacity. The service is offered by community member Vladimir.

The contracts were first offered beginning January 20, 2011<ref>[http://www.bitcoin.org/smf/index.php?topic=2883.0 selling contracts]</ref>. The operator had previously offered a to miners a [[Bitcoin Mining Operations Management Service|service]] where mining rigs could be managed by the operator remotely.

==External Links==

* [http://www.bitcointalk.org/index.php?topic=2883.0 selling contracts] forum thread

==References==
<references />

[[Category:Mining contractors]]

Help:Installing Bitcoin Core

2012-01-20T13:50:09Z

Wcoenen: updated download links to the latest bitcoin client version, 0.5.2

An account can effortlessly be created using an [[eWallet]] service. eWallet services provide an online wallet to hold your bitcoins.

This guide covers installing Bitcoin without needing a third party wallet service.

== For Windows computers ==

=== Installation ===
[http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.5.2/bitcoin-0.5.2-win32-setup.exe/download Download Bitcoin] and install it.

[[File:Install fin.png|frame|none|Complete installation wizard]]

=== Initialization ===

The first time you run Bitcoin, it needs to download all the blocks to setup. You already have your bitcoin address at this point, but you won't see any transactions before the initialisation is complete (it can take from half to a few hours).

[[File:First time run fin.png|frame|none|Bitcoin is initialising by establishing a connection to other clients and downloading the blocks.]]

[[File:Bitcoin all blocks fin.png|frame|none|Completed download of block-chain.]]

Your address (you can have as many as you want) is at the top. Below is your balance which will be zero. The list below shows your transactions.

== For Mac computers ==
[http://downloads.sourceforge.net/project/bitcoin/Bitcoin/bitcoin-0.5.2/bitcoin-0.5.2-macosx.dmg Download Bitcoin] and expand the disk image.

[[File:BcOSX.png|frame|none|Contents of the Bitcoin disk image after expansion]]

Drag the Bitcoin icon to the desired install location, and double-click the icon to run the application. The Bitcoin window will open and connections will start up in minutes. The blocks will begin downloading. Your address and balance are at the top of the window. Click "Copy to clipboard" to copy your address. Transactions are displayed in the main window.

[[File:BcOSXrunning.png|frame|none|Main window]]
[[File:BcOSXPreferences.png|frame|none|Preferences window on OS X]]

== Getting my first coins ==

The German Bitcoin market place [[bitcoin.de]] offers 0.01 BTC for every new [https://www.bitcoin.de/en/registrieren registered] user. The [[Bitcoin Faucet]] [https://freebitcoins.appspot.com/ website] currently hands out 0.001 BTC to new bitcoin users. Fill in the form with your bitcoin address. [http://www.wesmeredith.com/bitbybit/ Bit by Bit] is another website which provides.001 BTC for free and can be used daily. It also offers weekly lottery drawings for beginners. When you wish to add more, view [[Buying bitcoins]].

[[File:Get some btc.png|frame|none|Getting free coins from the Faucet]]

A new entry should appear in Bitcoin. The network hasn't yet confirmed it, but you know it's being processed. After about one hour it should get 6 confirmations. You are able to spend the coins when there is only one confirmation.

The confirmation counter (like the block counter) will increase by one roughly every 10 minutes. Six confirmations are considered as 100% sure a transfer has been processed.

[[File:First btc recv.png|frame|none]]

[[File:Six confirms bitcoin client.png|frame|none]]

* The [[Trade]] article shows hundreds of merchants who accept bitcoins.

== Buying Bitcoins ==

Bitcoins can be bought from individuals, on trading exchanges or from other online services. See the main page about [[Buying bitcoins|Buying Bitcoins]] for more information.

== Points to remember ==

* You don't need to be online to receive BTC.
* You can create as many new addresses as you like. Using a different address each time helps keep you [[Anonymity|anonymous]].
* You can be [[Anonymity|anonymous]] with adequate precautions.
* You cannot send BTC to an invalid address. Typos are not a worry as the payment will refuse to send.
* The [[Wallet|wallet]] file holds the keys that allow spending and thus the computer should be [[Securing_your_wallet|protected]] from the risk of loss and theft.
* Leaving Bitcoin open improves connectivity for the network and ensures that you don't fall behind on the block chain. Also see [[FAQ#Do_I_need_to_configure_my_firewall_to_run_bitcoin?|the FAQ about port forwarding]]

Proceed to the [[Introduction|introduction]]

== Technical ==
=== Block chain ===
The [[block chain]] is a never-ending story of every transaction throughout the network from day 1 (genesis). The first time you run Bitcoin, it is downloaded and verified on your computer. Every new transaction is added to the end of this chain and verified by the network to be valid.

=== Addresses ===
Whenever you send a coin, you are actually sending a cryptographically signed message, associating your coin with the recipient's address. This effectively transfers ownership to to the recipient. Once they own the coin, they are free to transfer it to another person.

A wallet is a collection of addresses. You can create as many new addresses as you wish; having more addresses makes you more anonymous, because then people cannot see how much BTC you received. Your wallet contains the secret keys used for spending that money, and must be [[Securing your wallet|backed-up regularly]]. If you lose the wallet then you no longer possess the money.

=== Generating ===
New coins are mined through generating hashes. These generators are rewarded with a small fee for the computationally intensive task of incorporating your transactions into the block-chain. This fee halves each time 210000 blocks are added to the block chain, or approximately every 4 years. The fee will keep halving until it effectively reaches zero, at which point 21 million coins will be in circulation.

[[Category:Introduction]]

[[de:Erste Schritte]]
[[zh-cn:入门]]

Help:Installing Bitcoin Core

2012-01-20T13:34:56Z

Wcoenen: Replaced section about Bitcoinmarket24.com with a link to the "Buying Bitcoins" page

An account can effortlessly be created using an [[eWallet]] service. eWallet services provide an online wallet to hold your bitcoins.

This guide covers installing Bitcoin without needing a third party wallet service.

== For Windows computers ==

=== Installation ===
[http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.5.1/bitcoin-0.5.1-win32-setup.exe/download Download Bitcoin] and install it.

[[File:Install fin.png|frame|none|Complete installation wizard]]

=== Initialization ===

The first time you run Bitcoin, it needs to download all the blocks to setup. You already have your bitcoin address at this point, but you won't see any transactions before the initialisation is complete (it can take from half to a few hours).

[[File:First time run fin.png|frame|none|Bitcoin is initialising by establishing a connection to other clients and downloading the blocks.]]

[[File:Bitcoin all blocks fin.png|frame|none|Completed download of block-chain.]]

Your address (you can have as many as you want) is at the top. Below is your balance which will be zero. The list below shows your transactions.

== For Mac computers ==
[http://downloads.sourceforge.net/project/bitcoin/Bitcoin/bitcoin-0.5.1/bitcoin-0.5.1-macosx.dmg Download Bitcoin] and expand the disk image.

[[File:BcOSX.png|frame|none|Contents of the Bitcoin disk image after expansion]]

Drag the Bitcoin icon to the desired install location, and double-click the icon to run the application. The Bitcoin window will open and connections will start up in minutes. The blocks will begin downloading. Your address and balance are at the top of the window. Click "Copy to clipboard" to copy your address. Transactions are displayed in the main window.

[[File:BcOSXrunning.png|frame|none|Main window]]
[[File:BcOSXPreferences.png|frame|none|Preferences window on OS X]]

== Getting my first coins ==

The German Bitcoin market place [[bitcoin.de]] offers 0.01 BTC for every new [https://www.bitcoin.de/en/registrieren registered] user. The [[Bitcoin Faucet]] [https://freebitcoins.appspot.com/ website] currently hands out 0.001 BTC to new bitcoin users. Fill in the form with your bitcoin address. [http://www.wesmeredith.com/bitbybit/ Bit by Bit] is another website which provides.001 BTC for free and can be used daily. It also offers weekly lottery drawings for beginners. When you wish to add more, view [[Buying bitcoins]].

[[File:Get some btc.png|frame|none|Getting free coins from the Faucet]]

A new entry should appear in Bitcoin. The network hasn't yet confirmed it, but you know it's being processed. After about one hour it should get 6 confirmations. You are able to spend the coins when there is only one confirmation.

The confirmation counter (like the block counter) will increase by one roughly every 10 minutes. Six confirmations are considered as 100% sure a transfer has been processed.

[[File:First btc recv.png|frame|none]]

[[File:Six confirms bitcoin client.png|frame|none]]

* The [[Trade]] article shows hundreds of merchants who accept bitcoins.

== Buying Bitcoins ==

Bitcoins can be bought from individuals, on trading exchanges or from other online services. See the main page about [[Buying bitcoins|Buying Bitcoins]] for more information.

== Points to remember ==

* You don't need to be online to receive BTC.
* You can create as many new addresses as you like. Using a different address each time helps keep you [[Anonymity|anonymous]].
* You can be [[Anonymity|anonymous]] with adequate precautions.
* You cannot send BTC to an invalid address. Typos are not a worry as the payment will refuse to send.
* The [[Wallet|wallet]] file holds the keys that allow spending and thus the computer should be [[Securing_your_wallet|protected]] from the risk of loss and theft.
* Leaving Bitcoin open improves connectivity for the network and ensures that you don't fall behind on the block chain. Also see [[FAQ#Do_I_need_to_configure_my_firewall_to_run_bitcoin?|the FAQ about port forwarding]]

Proceed to the [[Introduction|introduction]]

== Technical ==
=== Block chain ===
The [[block chain]] is a never-ending story of every transaction throughout the network from day 1 (genesis). The first time you run Bitcoin, it is downloaded and verified on your computer. Every new transaction is added to the end of this chain and verified by the network to be valid.

=== Addresses ===
Whenever you send a coin, you are actually sending a cryptographically signed message, associating your coin with the recipient's address. This effectively transfers ownership to to the recipient. Once they own the coin, they are free to transfer it to another person.

A wallet is a collection of addresses. You can create as many new addresses as you wish; having more addresses makes you more anonymous, because then people cannot see how much BTC you received. Your wallet contains the secret keys used for spending that money, and must be [[Securing your wallet|backed-up regularly]]. If you lose the wallet then you no longer possess the money.

=== Generating ===
New coins are mined through generating hashes. These generators are rewarded with a small fee for the computationally intensive task of incorporating your transactions into the block-chain. This fee halves each time 210000 blocks are added to the block chain, or approximately every 4 years. The fee will keep halving until it effectively reaches zero, at which point 21 million coins will be in circulation.

[[Category:Introduction]]

[[de:Erste Schritte]]
[[zh-cn:入门]]

Invoice address

2011-08-26T11:56:00Z

Wcoenen: updated difficulty of finding an address collision as compared to finding a block. I'm assuming 2^159 attempts are required on average, versus 2^52 for currently finding a block. 2^159 / 2^52 = 2^107

[[File:PubKeyToAddr.png|thumb|right|Conversion from ECDSA public key to Bitcoin Address]]
A '''Bitcoin Address''' is a 160-bit hash of the public portion of a public/private [[Wikipedia:Elliptic_Curve_DSA|ECDSA]] keypair. Using some mathemagic, you can "sign" data with your private key and anyone who knows your public key can verify that the signature is valid. See the [[Wikipedia:Public-key_cryptography|Wikipedia article]] for more information about how this works. See [[Protocol_specification#Addresses|protocol specification]] for details on how a bitcoin address is formed.

A new keypair is generated for each receiving address. Bitcoin addresses (the public keys) and their associated private keys are stored in the [[wallet]] data file. This is the only file you need to [[backup|back up]]. A "send" transaction to a specific Bitcoin address requires that the corresponding private key exist in the recipient's wallet. This has the implication that if you create a receiving address and receive coins to that address, then restore the wallet from an earlier backup, before the address was generated, then the coins associated with that address are lost. Addresses are added to an address [[key pool]] prior to being used for receiving coins. If you lose your wallet entirely, all of your coins are lost and can never be recovered.

"Generate" transactions happen in the same way as a send transaction: each batch of 50 generated coins is "sent" to a unique address that you generate just for that purpose. These addresses are also stored in your wallet, but they are not shown in the "your receiving addresses" section.

Bitcoin allows you to create as many addresses as you want, and each one is completely separate. There is no "master address": the "Your Bitcoin address" area in the Bitcoin UI has no special importance. It's only there for your convenience, and it will change automatically from time to time to enhance your anonymity. All of your other addresses will continue to work forever. They're listed in the "your receiving addresses" section. Each address takes up only about 500 bytes, so having a large number of addresses in your wallet is generally not a problem.

Bitcoin addresses contain a built-in check code, so it's generally not possible to send Bitcoins to a mistyped address. However, if the address is well-formed but no one owns it (or the owner lost their wallet.dat), any coins sent to that address will be lost forever.

Addresses can contain all alphanumeric characters except 0, O, I, and l. Normal addresses currently always start with 1, though this might change in a future version. Testnet addresses usually start with ''m'' or ''n''. Mainline addresses can be 25-34 characters in length, and testnet addresses can be 26-34 characters in length. Most addresses are 33 or 34 characters long, though.

It is also possible to send Bitcoins directly to an [[IP address]].

Since Bitcoin addresses are basically random numbers, it is possible, although extremely unlikely, for two people to independently generate the same address. This is called a [[Wikipedia:Collision_(computer_science)|collision]]. If this happens, then both the original owner of the address and the colliding owner could spend money sent to that address. It would not be possible for the colliding person to spend the original owner's entire wallet (or vice versa). If you were to intentionally try to make a collision, it would currently take 2^107 times longer to generate a colliding Bitcoin address than to generate a block. As long as the signing and hashing algorithms remain cryptographically strong, it will likely always be more profitable to collect generations and [[transaction fee|transaction fees]] than to try to create collisions.

[[Category:Technical]]
[[Category:Vocabulary]]