Bitcoin Wiki - User contributions [en]

Mining

2013-10-24T13:43:05Z

Lukasio: /* The mining ecosystem */

[[File:Quick-and-dirty-4x5970-cooling.jpg|thumb|right|A quick and dirty mining rig]]
== Introduction ==
'''Mining''' is the process of adding transaction records to Bitcoin's public ledger of past transactions.
This ledger of past transactions is called the [[block chain]] as it is a chain of [[block|blocks]].
The block chain serves to [[Confirmation|confirm]] transactions to the rest of the network as having taken place.
Bitcoin nodes use the block chain to distinguish legitimate Bitcoin transactions from attempts to re-spend coins that have already been spent elsewhere.

Mining is intentionally designed to be resource-intensive and difficult so that the number of blocks found each day by miners remains steady. Individual [[blocks]] must contain a [[proof of work|proof of work]] to be considered valid. This proof of work is verified by other Bitcoin nodes each time they receive a block.

The primary purpose of mining is to allow Bitcoin nodes to reach a secure, tamper-resistant consensus.
Mining is also the mechanism used to introduce Bitcoins into the system:
Miners are paid any transaction fees as well as a "subsidy" of newly created coins.
This both serves the purpose of disseminating new coins in a decentralized manner as well as motivating people to provide security for the system.

Bitcoin mining is so called because it resembles the mining of other commodities:
it requires exertion and it slowly makes new currency available at a rate that resembles the rate at which commodities like gold are mined from the ground.

== Difficulty ==
=== The Computationally-Difficult Problem ===
Mining a block is difficult because the SHA-256 hash of a block's header must be lower than or equal to the [[Target|target]] in order for the block to be accepted by the network. This problem can be simplified for explanation purposes: The hash of a block must start with a certain number of zeros. The probability of calculating a hash that starts with many zeros is very low, therefore many attempts must be made. In order to generate a new hash each round, a [[Nonce|nonce]] is incremented. See [[Proof of work]] for more information.

=== The Difficulty Metric ===
The [[Difficulty|difficulty]] is the measure of how difficult it is to find a new block compared to the easiest it can ever be. It is recalculated every 2016 blocks to a value such that the previous 2016 blocks would have been generated in exactly two weeks had everyone been mining at this difficulty. This will yield, on average, one block every ten minutes. As more miners join, the rate of block creation will go up. As the rate of block generation goes up, the difficulty rises to compensate which will push the rate of block creation back down. Any blocks released by malicious miners that do not meet the required difficulty [[Target|target]] will simply be rejected by everyone on the network and thus will be worthless.

=== Reward ===
When a block is discovered, the discoverer may award themselves a certain number of bitcoins, which is agreed-upon by everyone in the network. Currently this bounty is 25 bitcoins; this value will halve every 210,000 blocks. See [[Controlled Currency Supply]].

Additionally, the miner is awarded the fees paid by users sending transactions. The fee is an incentive for the miner to include the transaction in their block. In the future, as the number of new bitcoins miners are allowed to create in each block dwindles, the fees will make up a much more important percentage of mining income.

== The mining ecosystem ==

=== Hardware ===
[[File:Usb-fpga module 1.15x-hs-800.jpg|thumb|right|FPGA Module]]
Users have used various types of hardware over time to mine blocks. Hardware specifications and performance statistics are detailed on the [[Mining Hardware Comparison]] page.

=== Hosted mining ===
Allows users to mine bitcoins without owning physical hardware. The mining hardware is managed by the host and the customer recieves the bitcoins mined. This form of bitcoin mining is best for beginners or people who simply wish to profit from bitcoin mining without investing much time in it. [http://www.btcfarm.net btcfarm.net] is a company that offers hosted bitcoin mining.

==== CPU Mining ====
Early Bitcoin client versions allowed users to use their CPUs to mine. As the network hashrate grew with more power efficient GPU miners the amount of Bitcoin's produced by CPU mining became lower than the cost of power to operate the CPUS. The option still exists in the reference Bitcoin client, but it is disabled by default.

==== GPU Mining ====
GPU Mining is drastically faster and more efficient than CPU mining. See the main article: [[Why a GPU mines faster than a CPU]]. A variety of popular [[Mining rig|mining rigs]] have been documented.
==== FPGA Mining ====
FPGA mining is a very efficient and fast way to mine, comparable to GPU mining and drastically outperforming CPU mining. FPGAs typically consume very small amounts of power with relatively high hash ratings, making them more viable and efficient than GPU mining. See [[Mining Hardware Comparison]] for FPGA hardware specifications and statistics.
==== ASIC Mining ====
An application-specific integrated circuit, or ''ASIC'', is a microchip designed and manufactured for a very specific purpose. ASICs designed for Bitcoin mining were first released in 2013. For the amount of power they consume, they are vastly faster than all previous technologies and already has made GPU mining financially unwise in some countries and setups.

==== Mining services ====
Mining contracts - provides mining services with performance specified by contract. An example would be where a specific level of mining capacity is rented out for a set price for a specific duration. Short list of mining contractors is [[Minerlease]].

Mining shares - provides Mining as a Service (MaaS) model; break large-scale datacenter mining down to easily manageable pieces that are available in the form of shares of equipment. Mining shares are available from such companies as [[ASICMINER]] or [[Bit-miner.com]]

Hosted mining services create some systemic risk for the Bitcoin system because they undermine the security assumption that the control of mining power is well distributed. If too much mining becomes consolidated in large hosting providers and an attacker is able to compromise some of these providers they could potentially disrupt the Bitcoin system or rip off people they transact with with reversals.

=== Pools ===
As more and more miners competed for the limited supply of blocks, individuals found that they were working for months without finding a block and receiving reward for their mining efforts. This made mining something of a gamble. To address the variance in their income miners started organizing themselves into [[Pooled mining|pools]] so that they could share rewards more evenly. See [[Pooled mining]] and [[Comparison of mining pools]].

Similar to cloud mining traditional mining pools also create some potentially risky consolidation of control over hashing power. Although the individual miners are free to move to other pools if a pool misbehaves it can take days for them to notice misbehavior and react. Decentralized mining pools such as [[P2Pool]] exist to eliminate this risk but are more complicated to use.

=== History ===
Bitcoin's public ledger (the 'block chain') was started on January 3rd, 2009 at 18:15 UTC presumably by [[Satoshi Nakamoto]]. The first block is known as the [[genesis block]]. The first transaction recorded in the first block was a single transaction paying the reward of 50 new bitcoins to its creator.

==See Also==

* [http://codinginmysleep.com/bitcoin-mining-in-plain-english Bitcoin Mining in Plain English] by David Perry
* [[Automatically mine when computer is locked|Tutorial to automatically start mining when you lock your computer]]. (Windows 7)
* [http://www.reddit.com/r/Bitcoin/comments/18q2jx/eli5_bitcoin_mining_xpost_in_eli5/ Simplified Explanation of Bitcoin Mining] by reddit user [http://www.reddit.com/user/azotic azotic]

[[ru:Mining]]
[[Category:Mining]][[Category:Vocabulary]]

Selling bitcoins

2013-09-20T17:32:01Z

Lukasio: /* Fixed Rate Exchanges & Others */

There are various methods for selling bitcoins.

Warning: Please be careful with your money. When sending bitcoins to an exchange or other counterparty you are trusting that the counterparty will not abscond with your bitcoins and that the operator maintains secure systems that protect against theft -- internal or external. It is recommended that you obtain the real-world identity of the counterparty and ensure that sufficient recourse is available. Exchanging or storing significant funds with exchanges is not recommended.

==Market Exchanges==
Market exchanges are those in which buy orders are matched with sell orders, so the price offered depends on the market. If a service quotes a price then it is not operating a market but instead is a broker that buys and/or sells coins. Those exchanges are found in the list of fixed-rate exchanges.

{| class="wikitable"
|-
| Exchange || Adding Funds || Withdrawing Funds || Notes
|-
| [[BitBox]] || BTC USD (Wire Transfer - US) || BTC USD (Wire Transfer - US) || <ul><li>US-based</li><li>Two-factor Authentication</li><li>[http://inbitbox.github.io/rest/ BitBox REST API]</li><li>[https://github.com/inbitbox BitBox GitHub]</li></ul>
|-
| [[MtGox]] ||BTC USD (International bank wire) AUD (Bank wire) GBP (Bank wire) GBP (Cash deposit, Barclays) || BTC USD ([[Dwolla]]) AUD (Bank wire) || Restrictions and limits on withdrawals.
|-
| [[VirWoX]] || BTC SLL (Second Life) ACD (Avination) OMC (OpenSim) USD,EUR,GBP,CHF ([[PayPal]]) USD,EUR,GBP (Credit & Debit cards via [[Skrill]]/Moneybookers) USD,EUR,GBP ([[NETELLER]]) EUR (DIRECTebanking / Sofortüberweisung) USD,EUR,GBP,CHF ([[paysafecard]]) EUR (SEPA bank transfer) || BTC SLL (Second Life) ACD (Avination) OMC (OpenSim) USD,EUR,GBP,CHF ([[PayPal]]) USD,EUR,GBP ([[Skrill]]/Moneybookers) USD,EUR,GBP ([[NETELLER]]) EUR (SEPA bank transfer) || Trading through Second Life Linden Dollars (highly liquid). Variable limits on PayPal and Credit Card deposits.
|-
| [[Intersango]]([[Britcoin]]) || BTC GBP (bank deposit) EUR (SEPA bank deposit) PLN (bank transfer) || BTC GBP (bank deposit) EUR (SEPA bank transfer) PLN (bank transfer) ||
|-
| [[BTC-E]] || BTC BTC (BTC-e redeemable code) USD (Cash deposit at Post of Russia) USD (Cash deposit at banks including Privatbank, Savings Bank of Russia (Sberbank), RU/UA Terminals, & more) USD (Interkassa) USD (WebMoney - WMZ) USD (Yandex) USD (LiqPay) USD (Perfect Money) USD (QIWI) USD (OKPay) USD (RBK Money) USD (Ditial currencies including НСМЭП (NSMEP), Единый Кошелек (Unified Purse), TeleMoney, & more) USD (BTC-e Redeemable Code) USD (International bank wire) EUR (SEPA bank transfer) RUB (QIWI) RUB (LiqPay) RUB (WebMoney-WMR) RUB (BTC-e Redeemable code) RUB (Bank transfer) || BTC BTC (BTC-e redeemble code) USD (Webmoney - WMZ) USD (Perfect Money) USD (LiqPay) USD (QIWI) USD (PayPal) USD (OKPay) USD (Payza/AlertPay) USD (Privat, Privat UAH) USD (Cash deposit into Savings Bank/Sberbank, Telebank, Alfa Bank) USD (BTC-e Redeemable Code) USD (International Wire Transfer) EUR (SEPA bank transfer) RUB (Cash delivery, possible in Moscow) RUB (QIWI) RUB (LiqPay) RUB (WebMoney WMR) RUB (Яндекс.Деньги Yandex) RUB (RBK Money) Cash deposit (into account at Сбербанка России!/Savings Bank/Sberbank, Телебанк (Telebank), and АльфаБанк (Alfa Bank) RUB (Transfer to credit card VISA & MasterCard) RUB (BTC-e Redeemable code) RUB (Bank transfer) || Language: English, Russian.
|-
| [[VirtEx]] || BTC CAD (cash deposit at BMO Bank of Montreal) CAD (Online bill payment) CAD (Wire transfer) || BTC CAD (direct deposit) CAD (Canada Xpress Post Bank Draft send by mail) CAD Payza (formerly AlertPay) ||
|-
| [[Camp BX]] (CBX) || BTC USD ([[Dwolla]]) USD (P2P bank transfer at Chase, B of A, Wells Fargo and ING. Credited after three business days). USD (Personal Check) USD (USPS Postal money order, Canada Post money order) || BTC USD ([[Dwolla]]) USD (ACH Direct Deposit) USD (USPS Postal Money Order) USD (Domestic bank wire) USD (International bank wire) || <ul> <li> Security certification from McAfee</li><li> Advanced trading options with AON/FOK/Market</li> <li>STOPLOSS and Short-Selling in Pipeline</li><li> Trading API available</li><li> Wallet API available </li><li> CBX Instant Bitcoin Transfers Feature </li><li> Stoploss / Custom Order Expiry Date/Time </li><li> SMS (Text Message) Notifications </li> <li> Two-Factor Authentication </li> <li> Based in USA - Atlanta </li> </ul>
|-
| [[Bitstamp]] || BTC BTC (Redeemable code) EUR (SEPA transfer) USD (Intl wire) USD ([[Ripple]]) CHF || BTC BTC (Redeemable code) EUR (SEPA transfer) USD (Intl wire) USD (Ripple) CHF || EUR and CHF deposits converted to/from USD for trading
|-
| [[BTCTurk]] || BTC TL (Bank transfer) || BTC TL (Bank transfer) || <ul><li> The first Bitcoin exchange to allow trades in Turkish Lira.</li><li> Available in Turkish language. </li></ul>
|-
| [[FBTC Exchange]] || BTC USD(Domestic Wire Transfer) EUR (Bank transfer) || BTC USD EUR || Based in the Netherlands
|-
| [[FYB-SG]] || BTC SGD(Internet Bank Transfer) SGD (Annonymous Cash Deposit at any UOB Cash Deposit Machine in Singapore). || BTC SGD(Internet Bank Transfer) || <ul><li> Based in Singapore </li> </ul>
|-
| [[Rock Currency Exchange]] || BTC SLL (Second Life) USD ([[Dwolla]]) EUR (SEPA bank transfer) || BTC SLL (Second Life) USD ([[Dwolla]]) EUR (SEPA bank transfer) ||
|-
| [[bitNZ]] || BTC NZD (Cash deposit at Westpac) || BTC NZD (Domestic bank transfer) ||
|-
| [[Kapiton.se]] || BTC SEK (Bankgiro Bank Transfer) || BTC SEK (Bankgiro Bank Transfer) || ||
|-
| [[Vircurex]] || BTC || BTC || Trading in many other P2P/Crypto currencies possible
|-
|}

==Fixed Rate Exchanges & Others==

The following exchanges are either exchanges using a fixed rate based on other markets or are exchanges that enable you to redeem smaller amounts of bitcoins at reasonable rates:

* [http://coinmarket.co Coinmarket.co] Sell bitcoins for only 0.2% below market price. Get paid via paypal or wire transfer.
* [[24change.com]] Automatic Bitcoin and e-currencies buy/sell service Bitcoin, USD, UAH, RUB, Visa, MasterCard, EgoPay, Payoneer, MoneyGram, OKPAY, WireTransfer, QIWI, Yandex Money, PayPal, PerfectMoney, Paymer, ePayments, LiqPay, Redpass, WESTERN UNION, International Banks
* [[ALFAcashier]] Instant exchange between Bitcoin, Litecoin, PerfectMoney, QIWI, Yandex Money
* [[Bahtcoin]] Trade BTC for Thai Baht, cash, Webmoney, or Thai mobile and gaming prepaid cards.
* [[BTC China]] Market for exchanging bitcoins to and from CNY, withdraw CNY (Tencent, Alipay) and USD.
* [[BTCHKEX]] Trade your BTCs for HKD.
* [https://bips.me BIPS] ([[BIPS|info]]) Withdraw funds as Danish Domestic Transfer, or ACH / Direct Deposit in any current, and Wire Transfer to Any Country. DK-based
* [[BitBargain]] Market in the UK for buying bitcoins with GBP instantly from trusted OTC sellers through escrow.
* [[Bitcoil]] Exchange BTC for ILS with bank transfers in Israel
* [[Bitcoin Argentina]] Trades BTC for ARS. Cash and bank transfer. No exchange fees.
* [[Bitcoin Nordic]] Sell bitcoins with withdrawal to PayPal or bank transfer.
* [[Bitcoini.com]] Trade bitcoins in Bulgaria and Romania for local currencies, USD worldwide with Western Union, MoneyGram
* [http://BitcoinIsrael.co.il BitcoinIsrael.co.il] Get cash (ILS) for your Bitcoins within hours from any where in Israel.
* [[Bitcoiny.cz]] Trade your BTCs for CZK. No-escrow, direct person-to-person trading.
* [[bitcoin-otc]] IRC trading marketplace will usually have people willing to deal for small and larger amounts using various payment methods, including [[PayPal]], [[Dwolla]], [[Linden Dollars]], etc.
* [[Bitcoin.com.es]] Trade your BTCs for EUR (Bank transfer).
* [[bitcoin.de]] Trade your BTCs for EUR (bank wire, SEPA bank transfer, Money Bookers), person to person, eWallet
* [http://bitcoin.in.th/ Bitcoin in Thailand] Buy and Sell BTC in Thailand for cash via local bank deposits and transfers.
* [[bitcoin.local]] arranges for exchanging currencies in person with someone nearby
* [[Bitcoins In Berlin]] Trade your BTC for cash-in-the-mail (EUR), in-person trande, Western Union, Moneygram, bank transfer or SEPA.
* [[BitMarket.co]] Trade your BTCs for Colombian Peso (COP) as OTC with BTC Escrow.
* [[BitPiggy]] Trade your BTCs for AUD (Bank transfer).
* [https://www.bitquick.co BitQuick.co][https://en.bitcoin.it/wiki/BitQuick.co (info)] Instant exchange to receive cash deposit or SEPA transfer to the seller's bank account for Bitcoin at any price set by seller.
* [http://BTCInstant.com BTCinstant.com] Trade bitcoins for Virtual Credit Card (VCC, and specifically Virtual Mastercard brand) sent through e-mail.
* [[btcx.se]] / Btcx Sweden || 0% above 80 btc || SEK || Bank transfers to most Swedish banks within 4-12 hours.
* [[Canadian Bitcoins]] Buy/Sell Bitcoins in CAD and receive Cash, Cheque, Bank Transfer (TD Person Pay) or Interac.
* [[Cartão BitCoin]] Convert your bitcoins to reload your debit card (offered to Brazilians, accepted at 10,000 locations in Brazil)
* [[Coin2Pal]] Sell your Bitcoins and receive PayPal funds immediately.
* [[Coinabul]] Trade your BTCs for Gold/Silver
* [[Coinbase]] Sell bitcoins with proceeds delivered as a bank transfer (U.S., as ACH/direct deposit). Instant verification available for new accounts.
* [https://www.cryptxchange.com Cryptxchange] Sell bitcoins for USD or CAD Funds transfered VIA bank tranfer
* [[ECurrencyZone]] Cash out bitcoins to INR, BDT, MYR, SGD via bank transfer or cash deposited to your bank account. Also to Western Union, Moneygram, Citibank global funds transfer, Paypal, Skrill/Moneybookers, Payza/AlertPay, OKPay. Convert to digital currencies C-Gold, Perfect Money, WebMoney and EGOPay.
* [[FastCash4Bitcoins]] Sell your BTC and receive cash today. Over 100,000 BTC bought. Payments issued using your choice of PayPal, Dwolla, ACH (Direct Deposit), Bank Wire, Company Check, Cashier's Check or Silver Bullion even.
* [http://www.happycoins.nl HappyCoins] Buy and sell Bitcoins in Euro using the Dutch iDEAL or European SEPA payment system. Fast payout and transparent prices based on near real-time exchange prices (select from multiple exchanges).
* [[Mang Sweeney]] Use bitcoins to send remittance payments to the Philippines, in-person cash out in metro Manilla or from various remittance centers. Languages: English, Filipino.
* [[Lilion Transfer]] Exchanges bitcoins for [[Pecunix]], [[AlertPay]], [[Skrill]]/Moneybookers, [[PayPal]], and more.
* [[LocalBitcoins]] Exchanges bitcoins for csah, bank wirte transfers, [[OKPay]], [[AlertPay]], [[Skrill]]/Moneybookers, [[PayPal]], [[Dwolla]] and more.
* [[Nanaimo Gold]] Redeem bitcoins for money transfer, money order or direct deposit within Canada.
* [[Spend Bitcoins]] Sell bitcoins for AUD (Australia). Redeem for bank transfer, AustPost reloadable VISA, bill payment and other various methods.
* [http://jzn5w5pac26sqef4.onion.sh/ WeBuyBitcoins] Sell Bitcoins for ACH, PayPal, Cash In Mail, WU/MG.
* [http://localbitcoins.com LocalBitcoins.com] ([[LocalBitcoins|Info]]) Location-based bitcoin to cash exchange.
* [[OKPAY]] || Convert bitcoins from USD, EUR, GBP, RUB, CHF etc via bank wire transfer, USD, EUR via additional direct methods, USD, EUR via Migom, USD, EUR via Money Polo, USD, EUR via Intel Express, USD, EUR via Liqpay, USD, EUR, UAH via Wallet1, RUB via (Yandex Money) and USD via OKPAY Debit Card. Completely non-reversible payments. Support of 19 world currencies, 15 languages.
* [[Dagensia]] '''Fully licensed EU company''' exchanging Bitcoins, Bank Wire, SEPA EUR, Debit Cards. USD, EUR, GBP, CAD, CHF, SEK, AUD, CZK
* [http://artabit.com artaBit.com] ([[artaBit|info]]), Sell bitcoins in Indonesia for IDR (rupiah).
* [https://www.bitsofgold.co.il Bits Of Gold] ([[Bits of Gold|info]]), Sell bitcoins in Israel for ILS.
* [https://moneypaktrader.com MoneypakTrader.com] ([[MoneypakTrader.com|info]]), sell bitcoins for [[MoneyPak]].
* [[WM-Center]] Buy/sell Bitcoin, exchange Bitcoin to other e-currencies (such as Perfect Money, PayPal, EgoPay, c-gold, Pecunix, etc) and vice versa.

==Goods and Services==

One way of selling bitcoins is to use them as the payment method when making purchases.

See the [[Trade]] page for a fairly comprehensive list of goods and service that bitcoins will purchase.

==See Also==

* [[:Category:Digital currencies|Digital currencies]]
* [[Buying bitcoins]]
* [[Secure Trading]]
* [[:Category:Local|Local]] exchanges

[[Category:Exchanges]]
[[Category:Introduction]]

Main Page

2013-09-20T17:29:03Z

Lukasio:

Template:MainPage Topics

2013-09-08T11:50:13Z

Lukasio:

{|cellpadding="2" style="background-color: inherit;"
|-
| scope="col" style="width: 200px;" |
* [[Introduction]]
* [http://www.weusecoins.com/getting-started.php Getting started]
* [[Myths]]
* [http://bitcoin.gw.gd/-Bitcoin-News- News]

* [[Securing your wallet]]
* [http://www.quandl.com/markets/bitcoin Bitcoin Statistics]
| scope="col" style="width: 200px;" |
* [[PHP developer intro]]
* [[API reference (JSON-RPC)]]
* [[Protocol specification]]
* [[Secure Trading|Best practices for OTC traders]]
* [[Bitcoin Improvement Proposals]]
|}

{|cellpadding="2" style="background-color: inherit;"
|-
! scope="col" style="width: 200px;" |
! scope="col" style="width: 200px;" |
|-
|
* [http://www.minerlease.com Mining contracts]
* [[Software]]
* [[Mining]]
* [[:Category:Exchanges|Exchanges]]
* [[:Category:Directories|Local Directories]]
* [[:Category:Marketing|Marketing resources]]
* [[People]]
|
* [[:Category:Technical|Technical articles]]
* [[:Category:Clients|Clients]] / [[:Category:Frontends|Frontends]]
* [[:Category:Economics|Economics]]
* [[Trade|Businesses (Trade)]]
* [[:Category:Games|Games]]
* [[Real world shops|Real world merchants map]]
* [[Donation-accepting_organizations_and_projects|Donation-accepting sites]]
* [[Meetups]]
|}

<div style="text-align: right;" class="noprint">[{{fullurl:Template:MainPage_Topics|action=edit}} '''Edit'''] – '''[[Special:Categories|See More]]'''</div>

Buying Bitcoins (the newbie version)

2013-06-26T13:22:34Z

Lukasio:

This page aims to be the best resource for new users to understand how to buy Bitcoins.
The existing [[Buying bitcoins]] page is too complex, and not transparent enough for new investors.
Be extremely careful when buying bitcoins from not accredited websites or individuals. Like in the real world there are many scammers around.

{{Counterparty-warning}}

== Intro ==
[http://bitcoin.stackexchange.com/questions/2293/how-can-i-buy-bitcoin-via-a-credit-card-or-paypal You can't reliably buy Bitcoins using PayPal or credit cards], because it is risky for the seller, and therefore few sellers will offer this. There are basically 4 reasons for that:
* The TOS of PayPal actually prohibit buying digital currency with it
* The buyer of bitcoins can always perform a chargeback and there is no way for the seller to contest that
* There are many hacked accounts and when PayPal realizes that such an account has been fraudulently used, they will also perform a chargeback
* PayPal doesn't like bitcoin, as the bitcoin network is in direct competition to it

=== Anonymity ===
There is a HUGE demand for buying bitcoins off the grid due to ever-increasing government regulations and private agency intrusions and discrimination against alternative currencies.
Due to the possibility of facial recognition cameras at banks and the paper trail involved with credit cards, there are very few options to have high levels of anonymity when buying bitcoins those ways. DNA, Fingerprints, phone and internet records, audio and video records will not be discussed, but they all are possible tools which attackers could use to uncloak even the stealthiest bitcoin buyer.
There are a couple known ways, depending on your location, to buy bitcoins outside of the standard banking system with relatively high anonymity.
Buying locally with cash using a burner or payphone allows a high level of anonymity with the exchange being the weakest link.
Many sellers online will also trade bitcoins for [[MoneyPak]] codes or other cash-like gift codes which can be bought at a local store with cash.
Another way to buy bitcoins with a high level of anonymity is by sending cash in the mail.

=== Cash (International) ===
[http://www.paypaltobitcoin.com Pay2bit] allows you to buy bitcoins by mailing in cash. Low rates, fast customer service, and no account verification needed. This is the ONLY anonymous way to buy bitcoins, don't be fooled by other services. We don't report your transactions to any government, as soon as your transaction goes through all of your information is instantly wiped from our servers.

=== Via Bank Transfer (US) ===
[https://coinbase.com Coinbase] allows you to buy and sell bitcoin by connecting any U.S. bank account. You can start buying right away if you choose instant account verification.

=== Via IDeal (NL) ===
[https://bitonic.nl Bitonic] allows you to buy bitcoins with IDEAL.

=== Via Bank Transfer (EU) ===
[https://bitcoin-24.com Bitcoin-24.com] charges very low fees for SEPA transfers within the EU.
'''(Service not available/bank account frozen since April 12th)'''

=== Via Money Transfer ===
You can buy Bitcoins with a Western Union or MoneyGram money transfer via [http://www.coinmama.com/ coinmama.com].

=== Finding a direct seller online ===
If you can find another person that is willing to sell them to you, you can transfer him money via whatever method (including PayPal), and he'll send you the Bitcoins. The following websites can be used to find direct sellers online [[Bitcoin OTC]], [https://www.bitcoinary.com/ Bitcoinary] or the [https://bitcointalk.org/index.php?board=53.0 Currency Exchange Forum Section]. Be extremely cautious when using those methods, the best way is to ask an admin, moderator or a trusted person. Bitcoins are now also available at [http://www.amazon.com/gp/product/B00CPCHACM Amazon]. The seller only sells in low volumes so far, but it is a great way to turn amazon gift cards into bitcoin with no hassle, and probably one of the first ways to obtain bitcoin with a debit card or credit card.

=== Physical Trading ===
You might be able to find an individual you can [https://localbitcoins.com Buy bitcoins locally].
Always choose somebody with many reviews.

=== Bitinstant ===
You can buy Bitcoins via cash deposit or bank transfer using [[BitInstant]]. Here is a video tutorial explaining BitInstant: http://vimeo.com/44849463

=== Exchanges ===
The largest and most trusted exchange is [[MtGox]]. For a list of other major exchanges see [[Buying_bitcoins#Major_Exchanges|Major Exchanges]]

=== Blockchain (UK) ===
UK users used to be able to use [https://blockchain.info/wallet/deposit-pingit Barclays PingIt] or [https://blockchain.info/wallet/deposit-bank-transfer Bank Transfer] to purchase bitcoins from blockchain.info. All deposit options for UK/EU are now disabled.

=== Instant bank transfers within the EU and UK ===
Buy bitcoins via the instant Sofort network through [[Bitcoin-24]]. It is a very fast, easy and secure method to deposit Euro instantlly.

== Avoiding Scams ==
Before using any service it is a good idea to look for reviews and feedback from previous customers. This can be done by simply googling the name of the website or company. The bitcointalk forums are also a good place to find discussions and reviews about services.

==Exchange Directories==
* [http://howtobuybitcoins.com/ HowToBuyBitcoins.com]
* [http://howtobuybitcoins.info/ HowToBuyBitcoins.info]

== Links ==
* http://bitcoin.stackexchange.com/questions/91/how-do-you-obtain-bitcoins
* http://bitcoin.stackexchange.com/questions/4194/whats-the-best-way-to-buy-bitcoin-noob-friendly
* [[Buying bitcoins]]
* http://www.reddit.com/r/Bitcoin/comments/nzg4o/the_canonical_newbie_guide_to_bitcoin/c3d5tmc

[[Category:Introduction]]

Minerlease

2013-06-06T14:46:36Z

Lukasio: /* External Links */

== Minerlease ==

Sells mining contracts in 1, 0.5 or 0.2 Gigahash units.

The service is quoted to begin mining in September 2013<ref>[http://www.minerlease.com/contracts/1year/]</ref>. They use BFL rigs initially due to its low power consumption. Current Hash rate on preorder with BFL is 5 Thash.

==External Links==

* [http://www.minerlease.com Website]

==References==
<references />

[[Category:Mining contractors]]
[[Category:Mining]]
[[Category:Mining contracts]]
[[Category:ASIC mining]]

Mining

2013-06-05T21:45:02Z

Lukasio:

[[File:Quick-and-dirty-4x5970-cooling.jpg|thumb|right|A quick and dirty mining rig]]
== Introduction ==
'''Mining''', or generating, is the process of adding transaction records to Bitcoin's public ledger of past transactions. This ledger of past transactions is called the [[block chain]] as it is a chain of [[block|blocks]]. The block chain serves to [[Confirmation|confirm]] transactions to the rest of the network as having taken place. Bitcoin nodes use the block chain to distinguish legitimate Bitcoin transactions from attempts to respend coins that have already been spent elsewhere.

Mining is intentionally designed to be resource-intensive and difficult so that the number of blocks found each day by miners remains steady. Individual [[blocks]] must contain a [[proof of work|proof of work]] to be considered valid. This proof of work is verified by other Bitcoin nodes each time they receive a block.

== History ==
Bitcoin's public ledger (the 'block chain') was started on January 3rd, 2009 at 18:15 UTC presumably by [[Satoshi Nakamoto]]. The first block is known as the [[genesis block]]. The first transaction recorded in the first block was a single transaction paying the reward of 50 new bitcoins to its creator.

Bitcoin mining is so called because it resembles the mining of other commodities: it requires exertion and it slowly makes new currency available at a rate that resembles the rate at which commodities like gold are mined from the ground. See [[Controlled Currency Supply]].

== Mining contracts ==
Provides mining services with performance specified by contract. An example would be where a specific level of mining capacity is rented out for a set price for a specific duration. One of the biggest mining contractors is [[Minerlease]]

== Difficulty ==
=== The Computationally-Difficult Problem ===
Mining a block is difficult because the SHA-256 hash of a block's header must be lower than or equal to the [[Target|target]] in order for the block to be accepted by the network. This problem can be simplified for explanation purposes: The hash of a block must start with a certain number of zeros. The probability of calculating a hash that starts with many zeros is very low, therefore many attempts must be made. In order to generate a new hash each round, a [[Nonce|nonce]] is incremented. See [[Proof of work]] for more information.

=== The Difficulty Metric ===
The [[Difficulty|difficulty]] is the measure of how difficult it is to find a new block compared to the easiest it can ever be. It is recalculated every 2016 blocks to a value such that the previous 2016 blocks would have been generated in exactly two weeks had everyone been mining at this difficulty. This will yield, on average, one block every ten minutes. As more miners join, the rate of block creation will go up. As the rate of block generation goes up, the difficulty rises to compensate which will push the rate of block creation back down. Any blocks released by malicious miners that do not meet the required difficulty [[Target|target]] will simply be rejected by everyone on the network and thus will be worthless.

=== Reward ===
When a block is discovered, the discoverer may award themselves a certain number of bitcoins, which is agreed-upon by everyone in the network. Currently this bounty is 25 bitcoins; this value will halve every 210,000 blocks. See [[Controlled Currency Supply]].

Additionally, the miner is awarded the fees paid by users sending transactions. The fee is an incentive for the miner to include the transaction in their block. In the future, as the number of new bitcoins miners are allowed to create in each block dwindles, the fees will make up a much more important percentage of mining income.

== Hardware ==
[[File:Usb-fpga module 1.15x-hs-800.jpg|thumb|right|FPGA Module]]
Users have used various types of hardware over time to mine blocks. Hardware specifications and performance statistics are detailed on the [[Mining Hardware Comparison]] page.
=== CPU Mining ===
Early Bitcoin client versions allowed users to use their CPUs to mine. The advent of GPU mining made CPU mining financially unwise. The option was therefore removed from the Bitcoin client.
=== GPU Mining ===
GPU Mining is drastically faster and more efficient than CPU mining. See the main article: [[Why a GPU mines faster than a CPU]]. A variety of popular [[Mining rig|mining rigs]] have been documented.
=== FPGA Mining ===
FPGA mining is a very efficient and fast way to mine, comparable to GPU mining and drastically outperforming CPU mining. FPGAs typically consume very small amounts of power with relatively high hash ratings, making them more viable and efficient than GPU mining. See [[Mining Hardware Comparison]] for FPGA hardware specifications and statistics.
=== ASIC Mining ===
An application-specific integrated circuit, or ''ASIC'', is a microchip designed and manufactured for a very specific purpose. ASICs designed for Bitcoin mining were first released in 2013 and (at the time of this writing) are in the hands of a very limited number of miners. For the amount of power they consume, they are expected to be vastly faster than all previous technologies and will likely make GPU mining financially unwise.

== Pools ==
As mining a block became more and more difficult, individuals found that they were working for months without finding a block and receiving ''any'' reward for their mining efforts. Thus they started organizing themselves into [[Pooled mining|pools]] so that they could share rewards more evenly. See [[Pooled mining]] and [[Comparison of mining pools]].
[[Category:Mining]][[Category:Vocabulary]]

==See Also==

* [http://codinginmysleep.com/bitcoin-mining-in-plain-english Bitcoin Mining in Plain English] by David Perry
* [[Automatically mine when computer is locked|Tutorial to automatically start mining when you lock your computer]]. (Windows 7)

Marchenko Ltd

2013-06-04T15:57:25Z

Lukasio:

Sold contracts for purchasing mining rig capacity. The service was 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 />

Marchenko Ltd

2013-06-04T15:57:08Z

Lukasio:

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 />

21bitcoin

2013-06-04T15:56:26Z

Lukasio:

21bitcoin mining pool is a Hong Kong based mining pool (web front located in US).

Opened in June 20, 2011, 21bitcoin mining pool is grown up to the most vigorous mining pool in Chinese Netsphere. The pool operator also sells mining contracts<ref>[http://forum.bitcoin.org/index.php?topic=17208.0 HK mining contract]</ref>.

於2011年6月20日正式開始運營，21bitcoin礦場正成爲中文網絡圈中最具活力的礦場。

==See Also==

* [[Comparison of mining pools]]

==External Links==

* [http://21bitcoin.com/pool 21bitcoin 礦場] 是一個香港的礦場（網站前端設置在美國）

==References==
<references />

[[Category:Pool Operators]]

Minerlease

2013-06-04T14:54:08Z

Lukasio: /* Minerlease */ new section

== Minerlease ==

Sells mining contracts in 1, 0.5 or 0.2 Gigahash units.

The service is quoted to begin mining in September 2013<ref>[http://www.minerlease.com/contracts/1year/]</ref>. They use BFL rigs initially due to its low power consumption. Current Hash rate on preorder with BFL is 5 Thash.

==External Links==

* [http://www.minerlease.com] Website

==References==
<references />

[[Category:Mining contractors]]
[[Category:Mining]]
[[Category:Mining contracts]]
[[Category:ASIC mining]]

Category:Mining contractors

2013-06-04T14:39:14Z

Lukasio:

Provides mining services with performance specified by contract. An example would be where a specific level of mining capacity is rented out for a set price for a specific duration.
One of the biggest mining contractors is minerlease.com.

[[Category:Mining]]

Category:Mining contractors

2013-06-04T14:38:31Z

Lukasio: