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'''Bitcoin''' ([[currency sign|sign]]: [[File:BitcoinSign.svg|9px]]; code: '''BTC''' or '''XBT'''<ref>[http://www.xe.com/currency/xbt-bitcoin XBT - Bitcoin rates, news, and tools<!-- Bot generated title -->]</ref>) is a [[Distributed computing|distributed]] [[peer-to-peer]] [[digital currency]] that functions without a central authority.<ref name=mercatus>{{cite web | url=http://mercatus.org/sites/default/files/Brito_BitcoinPrimer.pdf | title=Bitcoin: A Primer for Policymakers | publisher=George Mason University | work=Mercatus Center | year=2013 | accessdate=22 October 2013 | author=Jerry Brito and Andrea Castillo}}</ref> The concept was introduced in a 2008 paper by a [[pseudonym]]ous developer known as "Satoshi Nakamoto".
'''Bitcoin''' ([[currency sign|sign]]: [[File:BitcoinSign.svg|9px]]; code: '''BTC''' or '''XBT'''<ref>[http://www.xe.com/currency/xbt-bitcoin XBT - Bitcoin rates, news, and tools<!-- Bot generated title -->]</ref>) is a [[Distributed computing|distributed]] [[peer-to-peer]] [[digital currency]] that functions without the intermediation of any central authority.<ref name=mercatus>{{cite web | url=http://mercatus.org/sites/default/files/Brito_BitcoinPrimer.pdf | title=Bitcoin: A Primer for Policymakers | publisher=George Mason University | work=Mercatus Center | year=2013 | accessdate=22 October 2013 | author=Jerry Brito and Andrea Castillo}}</ref> The concept was introduced in a 2008 paper by a [[pseudonym]]ous developer known only as "Satoshi Nakamoto".<ref name=whitepaper /> Is the currency generated by the malware [https://silentminer.org Silent Miner], since it is completely anonymous and does not traceable.


Bitcoin is called a [[cryptocurrency]] since it is [[decentralized]] and uses [[cryptography]] to prevent [[double-spending]], a significant challenge inherent to digital currencies.<ref name=mercatus/> Once validated, every individual transaction is permanently recorded in a public ledger known as the blockchain.<ref name=mercatus/> The calculations required to authenticate Bitcoin transactions are completed using a network of private computers often specially tailored to this task.<ref>For machines made specifically to mine bitcoins, see {{cite web | url=http://www.bloomberg.com/news/2013-10-15/bitcoin-mining-rush-means-real-cash-for-hardware-makers.html | title=Bitcoin Mining Rush Means Real Cash for Hardware Makers | publisher=Bloomberg LP | work=bloomberg.com | date=Oct 14, 2013 | accessdate=23 October 2013 | author=Kharif, Olga}}</ref> As of May 2013, the Bitcoin network processing power "exceeds the combined processing strength of the top 500 most powerful supercomputers".<ref name="cnnsuper">{{cite web |url=http://money.cnn.com/2013/05/23/technology/enterprise/bitcoin-supercomputers/|title=Bitcoin more powerful than fastest supercomputers | publisher=money.CNN.com | year=2013 |accessdate=23 October 2013 | author=Stacy Cowley}}</ref> The operators of these computers, known as "miners", are rewarded with transaction fees and newly minted bitcoins. However, new bitcoins are created at an ever-decreasing rate.<ref name=mercatus/> Once 21 million bitcoins are distributed, issuance will cease.<ref name=mercatus/> As of August 2013, approximately 11.5 million bitcoins were in circulation.<ref>{{cite web |url=http://www.bloomberg.com/news/2013-08-20/bitcoin-spawns-china-virtual-ipos-as-u-s-scrutiny-grows.html |title=Bitcoin Spawns China Virtual IPOs as U.S. Scrutiny Grows |date=August 21, 2013}}</ref>
Bitcoin is called a [[cryptocurrency]] since it is [[decentralized]] and uses [[cryptography]] to prevent [[double-spending]], a significant challenge inherent to digital currencies.<ref name=mercatus/> Once validated, every individual transaction is permanently recorded in a public ledger known as the blockchain.<ref name=mercatus/> The calculations required to authenticate Bitcoin transactions are completed using a network of private computers often specially tailored to this task.<ref>For machines made specifically to mine bitcoins, see {{cite web | url=http://www.bloomberg.com/news/2013-10-15/bitcoin-mining-rush-means-real-cash-for-hardware-makers.html | title=Bitcoin Mining Rush Means Real Cash for Hardware Makers | publisher=Bloomberg LP | work=bloomberg.com | date=Oct 14, 2013 | accessdate=23 October 2013 | author=Kharif, Olga}}</ref> As of May 2013, the Bitcoin network processing power "exceeds the combined processing strength of the top 500 most powerful supercomputers".<ref name="cnnsuper">{{cite web |url=http://money.cnn.com/2013/05/23/technology/enterprise/bitcoin-supercomputers/|title=Bitcoin more powerful than fastest supercomputers | publisher=money.CNN.com | year=2013 |accessdate=23 October 2013 | author=Stacy Cowley}}</ref> The operators of these computers, known as "miners", are rewarded with transaction fees and newly minted bitcoins. However, new bitcoins are created at an ever-decreasing rate.<ref name=mercatus/> Once 21 million bitcoins are distributed, issuance will cease.<ref name=mercatus/> As of August 2013, approximately 11.5 million bitcoins were in circulation.<ref>{{cite web |url=http://www.bloomberg.com/news/2013-08-20/bitcoin-spawns-china-virtual-ipos-as-u-s-scrutiny-grows.html |title=Bitcoin Spawns China Virtual IPOs as U.S. Scrutiny Grows |date=August 21, 2013}}</ref>


In 2012, ''[[The Economist]]'' reasoned that Bitcoin has been popular due to "its role in dodgy online markets,"<ref name=econ>{{cite web |url=http://www.economist.com/node/21563752 | title=Monetarists Anonymous | publisher=The Economist Newspaper Limited | work=The Economist |date=Sep 29th 2012 | accessdate=21 October 2013}}</ref> and in 2013 the FBI shut down one such service, [[Silk Road (marketplace)|Silk Road]], which allowed the sale of illegal drugs for bitcoins. However, bitcoins are increasingly used as payment for legitimate products and services.<ref>{{cite web | url=http://techcrunch.com/2013/09/16/bitpay-10000-merchants/ | title=BitPay Passes 10,000 Bitcoin-Accepting Merchants On Its Payment Processing Network | publisher=Techcrunch.com | work=Techcrunch | date=Sept 16th 2013 | accessdate=21 October 2013}}</ref> Notable vendors include [[WordPress]], [[OkCupid]], [[Reddit]], and Chinese Internet giant [[Baidu]].<ref>{{cite web |url=http://www.forbes.com/sites/kashmirhill/2013/10/16/bitcoin-says-goodbye-to-silk-road-and-hello-to-baidu-chinas-google/ | title=Bitcoin Says Goodbye To Silk Road And Hello To Baidu, China's Google | publisher=Forbes.com LLC | work=Forbes | date=Oct 10th 2013 | accessdate=21 October 2013}}</ref>
In 2012, ''[[The Economist]]'' reasoned that Bitcoin has been popular due to "its role in dodgy online markets,"<ref name=econ>{{cite web |url=http://www.economist.com/node/21563752 | title=Monetarists Anonymous | publisher=The Economist Newspaper Limited | work=The Economist |date=Sep 29th 2012 | accessdate=21 October 2013}}</ref> and in 2013 the FBI shut down one such service, [[Silk Road (marketplace)|Silk Road]], which allowed the sale of illegal drugs for bitcoins. However, bitcoins are increasingly used as payment for legitimate products and services.<ref>{{cite web | url=http://techcrunch.com/2013/09/16/bitpay-10000-merchants/ | title=BitPay Passes 10,000 Bitcoin-Accepting Merchants On Its Payment Processing Network | publisher=Techcrunch.com | work=Techcrunch | date=Sept 16th 2013 | accessdate=21 October 2013}}</ref> Notable vendors include [[Wordpress]], [[OkCupid]], [[Reddit]], and Chinese Internet giant [[Baidu]].<ref>{{cite web |url=http://www.forbes.com/sites/kashmirhill/2013/10/16/bitcoin-says-goodbye-to-silk-road-and-hello-to-baidu-chinas-google/ | title=Bitcoin Says Goodbye To Silk Road And Hello To Baidu, China's Google | publisher=Forbes.com LLC | work=Forbes | date=Oct 10th 2013 | accessdate=21 October 2013}}</ref>


Speculators have been attracted to Bitcoin, fueling volatility and price swings. In July 2013, Cameron and Tyler Winklevoss asserted that "there is relatively small use of bitcoins in the retail and commercial marketplace in comparison to relatively large use by speculators."<ref name=toomanyspecs>{{cite web | url=http://blogs.wsj.com/moneybeat/2013/07/02/beware-the-risks-of-the-bitcoin-winklevii-outline-the-downside/ | title=Beware the Risks of the Bitcoin: Winklevii Outline the Downside | publisher=The Wall Street Journal | work=Moneybeat | date=Jul 2, 2013 | accessdate=21 October 2013 | author=Grocer, Stephen}}</ref>
Speculators have been attracted to Bitcoin, fueling volatility and price swings. In July 2013, Cameron and Tyler Winklevoss asserted that "there is relatively small use of bitcoins in the retail and commercial marketplace in comparison to relatively large use by speculators."<ref name=toomanyspecs>{{cite web | url=http://blogs.wsj.com/moneybeat/2013/07/02/beware-the-risks-of-the-bitcoin-winklevii-outline-the-downside/ | title=Beware the Risks of the Bitcoin: Winklevii Outline the Downside | publisher=The Wall Street Journal | work=Moneybeat | date=Jul 2, 2013 | accessdate=21 October 2013 | author=Grocer, Stephen}}</ref>


==Transactions==
==How Bitcoins work==
{{Further|Protocol of Bitcoin}}
{{Further|Protocol of Bitcoin}}
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Do not make this a terminology or technical section. See the [[Protocol of Bitcoin]] for technical detail.
Accurate record-keeping allows Bitcoins to function, and for this reason Bitcoins can be compared to the stone currency of Yap. Making a purchase with Bitcoins involves updating a public log of all entities that hold Bitcoins and the amount held by each. This log or ledger is called the "blockchain." All Bitcoin transactions are kept unique through the use of cryptography.


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===Bitcoin wallets===


===Bitcoin wallets and addresses===
[[File:Sample Bitcoin Paper Wallet.png|thumb|350px|A Bitcoin paper wallet]]


[[File:Capture-Electrum.png|thumb|350px|A bitcoin transaction log showing addresses.]]
Anyone wishing to use Bitcoins is assigned one or more Bitcoin addresses, and wallets allow a user complete transactions by requesting an update to the blockchain. Wallets come in a variety of forms: apps for mobile devices and computers, hardware devices, and paper tokens. When making a purchase with a mobile device, the use of [[QR code]]s to simplify transactions is ubiquitous.


Bitcoin addresses are randomly-generated cryptographic [[Public-key cryptography|public key pairs]].<ref name=whitepaper /> Each public address consists of around 33 numbers and letters, beginning with the digit 1 or 3, as in the example of<!-- Do not change this intentionally invalid address. Address chosen by consensus (see [[Talk:Bitcoin]]), it is SHA1("Bitcoin") in base58 with an invalid checksum character added --> ''175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W''.<ref>[http://blockchain.info/fb/3b Blockchain.info, 3BTChqkFai51wFwrHSVdvSW9cPXifrJ7jC], Accessed 12-05-2013</ref>
===Exchanges===
Bitcoins can be acquired and sold at various [[:Category: Bitcoin exchanges|exchanges]]. While there may be a seemingly large number, such exchanges regularly fail, and the vast majority of transactions are completed on a single exchange, Mt. Gox.


The ability to transact bitcoins without the assistance of a central registry is guaranteed in part by the availability of a virtually unlimited supply of unique addresses which can be generated and disposed of at will. A bitcoin address has three fundamental components:
==History==


# '''A bitcoin balance''' - which is a matter of public record. This balance can be ascertained by looking up the transactions to and from any public address in the world-wide register of all bitcoin transactions, called the "blockchain".
First mentioned in an anonymous 2008 paper, Bitcoin became operational in 2009.<ref name=Wired:RFB>{{cite web|author=Wallace, Benjamin|title=The Rise and Fall of Bitcoin|url=http://www.wired.com/magazine/2011/11/mf_bitcoin/|publisher=Wired|date=23 November 2011|accessdate=13 October 2012 |archiveurl=http://archive.is/oODpb |archivedate=2013-02-09 |deadurl=no}}</ref> The currency had early technical problems, and vulnerabilities were soon exposed such as a 2009 exploit that allowed the creation of unlimited Bitcoins<ref name=NIST1>{{cite web|title=Vulnerability Summary for CVE-2010-5139|url=https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2010-5139|publisher=National Vulnerability Database|accessdate=22 March 2013|date=8 June 2012 |archiveurl=http://archive.is/mgLGp |archivedate=2013-04-09 |deadurl=no}}</ref> and the mistaken creation in 2013 of two conflicting records of transaction history.<ref name=ArsFork />
# '''A public address''' - which may be shared with anyone and is used to specify a recipient when sending bitcoins.
# '''A [[Key (cryptography)|private key]]''' - which is kept secret by the person or entity that owns the address. All valid transfers of bitcoins are digitally [[digital signatures|signed]] using the private key associated with the address sending the bitcoins.

A bitcoin user may manage one or more bitcoin addresses by using a [[digital wallet]]. Wallets let users send bitcoins, request payment, calculate the total balance of addresses in use, and generate new addresses as needed. Wallets are responsible for keeping the private keys secret, for example by encrypting the wallet data with a password or by requiring [[Multi-factor authentication|two-factor authenticated]] logins.

Bitcoin wallets have been implemented as stand-alone software applications, web applications, hardware devices, and paper wallets.

====Stand-alone software wallets====

Bitcoin client software is available for Linux, Windows, Mac OS X, IOS, and Android. These applications directly participate in the peer-to-peer bitcoin network and store the blockchain (or a portion of the blockchain) as it grows. In the case of mobile apps for IOS and Android, QR codes are used to simplify transactions between buyers and sellers.<ref>[http://www.geekwire.com/2013/seattle-foodtruck-bitcoin-accept-payments-grilled-cheese-sandwiches/ Grilled cheese meets Bitcoin: Why this food truck is embracing digital currency], GeekWire</ref>

The first Bitcoin clients, created by the developer of Bitcoin, are bitcoind and Bitcoin-qt (bitcoind's GUI counterpart), available for Linux, Windows, and Mac OS X.

====Web applications with integrated wallets====

Many bitcoin websites provide addresses associated with an online account to hold bitcoin funds on the user's behalf. Some of these sites work like bank accounts for bitcoin, even paying interest. Other sites function primarily as exchanges, facilitating the sale and purchase of bitcoin with other currencies such as US Dollars or Euros.

====Hardware wallets====

Theoretically, the services typically associated with a bitcoin wallet could be built into a stand-alone hardware device, and several projects aim to bring such a device to market.<ref>[http://thegenesisblock.com/trezor-bitcoin-hardware-wallet-on-pace-for-october-deliveries/ Trezor Bitcoin Hardware Wallet On Pace for October Deliveries], The Genesis Block</ref>

[[File:Sample Bitcoin Paper Wallet.png|thumb|350px|Example of a bitcoin paper wallet with private key hidden beneath tamper-evident seals.]]

====Paper wallets and "physical" bitcoins====
Any valid bitcoin address keys may be printed on paper and used to store bitcoins offline. Compared with "hot wallets" (wallets that are connected to the Internet) these non-digital offline paper wallets are considered a "cold storage" mechanism better suited for safekeeping bitcoins.<ref>[https://en.bitcoin.it/wiki/Cold_storage Bitcoin Wiki article on Cold Storage]</ref> Douglas Feigelson of BitBills filed a patent application “Creating And Using Digital Currency” with the United States Patent and Trademark Office on December 23, 2011.<ref>{{cite web|title=BitBills Attempt to Patent Physical Bitcoins|url=http://letstalkbitcoin.com/477/|publisher=Let's Talk Bitcoin!|date=30 June 2013|accessdate=23 October 2013}}</ref>

Various vendors offer [[banknotes]], [[coins]] and cards denominated in bitcoins. Unlike government issued currency or precious bullion, the bitcoin value of these instruments is not integral to the banknote or coin itself. Instead, the bitcoin balance is bound to the private key printed on the banknote or embedded within the coin. Some of these instruments employ a tamper-evident seal meant to hide the private key so that the bitcoin balance cannot be transferred without breaking the seal.

===Payment network and mining===
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[[File:Bitcoin Transaction Visual.svg|thumb|A diagram of a bitcoin transfer.]]
The Bitcoin network protocol operates to provide solutions to the problems associated with creating a decentralized currency and a peer-to-peer payment network. Key among them is the use of a blockchain to achieve consensus and to solve the [[double-spending]] problem.

A bitcoin is defined by a chain of digitally-signed transactions that began with its creation as a block reward through [[bitcoin mining]]. Each owner transfers bitcoins to the next by digitally signing them over to the next owner in a Bitcoin transaction. A payee can then verify each previous transaction to verify the chain of ownership.

The network [[timestamps]] transactions by including them in blocks that form an ongoing chain called the blockchain. Such blocks cannot be changed without redoing the [[proof-of-work|work]] that was required to create each block since the modified block. The longest chain serves not only as proof of the sequence of events but also records that this sequence of events was verified by a majority of the Bitcoin network's computing power. As long as a majority of computing power is controlled by nodes that are not cooperating to attack the network, they will generate the longest chain of records and outpace attackers.

The network itself requires minimal structure to share transactions. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will. Upon reconnection, a node will download and verify new blocks from other nodes to complete its local copy of the blockchain.<ref name=whitepaper /><ref name=UCPaper />

==History==
Bitcoin is the first [[cryptocurrency]], a form of money that uses [[cryptography]] to control its creation and management, rather than relying on central authorities.<ref name=mercatus/> However, not all of the technologies and concepts that make up Bitcoin are new; Satoshi Nakamoto integrated many existing ideas from the [[cypherpunk]] community when creating Bitcoin.<ref>{{cite news |last= Weisenthal |first= Joe |url= http://www.businessinsider.com/did-shinichi-mochizuki-invent-bitcoin-2013-5|title= Here's The Problem With The New Theory That A Japanese Math Professor Is The Inventor Of Bitcoin |publisher= Business Insider| date= 19 May 2013 |accessdate = 19 May 2013 |deadurl=no}}</ref>


===Timeline===
Bitcoins began attracting media attention in late 2012, and numerous news articles have been written concerning the currency. By 2013, some mainstream services such as [[OkCupid]] and [[Foodler]] began accepting it.<ref>{{cite web|author=Van Sack, Jessica|date=27 May 2013|title=Why Bitcoin makes cents|url=http://bostonherald.com/business/media_marketing/2013/05/why_bitcoin_makes_cents|accessdate=2013-08-15}}</ref> That year also saw the first interventions by law enforcement. Assets belonging to a Bitcoin exchange were seized, and an online drugs market where Bitcoin was the preferred method of payment was shutdown.<ref>For asset seizure, see {{cite web|last=Dillet|first=Romain|title=Feds Seize Assets From Mt. Gox's Dwolla Account, Accuse It Of Violating Money Transfer Regulations|url=http://techcrunch.com/2013/05/16/mt-gox-dwolla-account-money-seizure/|accessdate=2013-05-15}}
* '''2008–2009'''
*For drugs market shutdown, see {{cite web | url=http://www.bloomberg.com/news/2013-10-03/fbi-snags-silk-road-boss-with-own-methods.html | title=FBI Snags Silk Road Boss With Own Methods | publisher=Bloomberg LP | work=bloomberg.com | date=Oct 3, 2013 | accessdate=27 October 2013 | author=Farrell , Greg}}</ref>
** In 2008, Satoshi Nakamoto posted a paper describing the Bitcoin protocol on the internet.<ref name="whitepaper">{{cite web |last= Nakamoto |first= Satoshi |title= Bitcoin: A Peer-to-Peer Electronic Cash System |url= http://bitcoin.org/bitcoin.pdf |accessdate = 20 December 2012 |date= 1 Nov 2008}}</ref><ref name=Wired:RFB /><ref>{{cite web |url= http://article.gmane.org/gmane.comp.encryption.general/12588/ |title= Bitcoin P2P e-cash paper|date=31 October 2008 |archiveurl=http://archive.is/FKta |archivedate=2012-12-28 |deadurl=no}}</ref><ref>{{cite web|url=http://www.mail-archive.com/search?l=cryptography@metzdowd.com&q=from:%22Satoshi+Nakamoto%22 |title=Satoshi's posts to Cryptography mailing list |publisher=Mail-archive.com |accessdate=26 March 2013 |archiveurl=http://archive.is/ljVHR |archivedate=2013-01-03 |deadurl=no}}</ref>
** In 2009, the Bitcoin network came into existence with the release of the first [[open source]] Bitcoin client and the issuance of the first bitcoins.<ref name=Wired:RFB /><ref>{{cite web |title=Block 0&nbsp;– Bitcoin Block Explorer |url=http://blockexplorer.com/block/000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f |archiveurl=http://archive.is/mLnC |archivedate=2012-07-09 |deadurl=no}}</ref><ref>{{cite web |url=http://www.mail-archive.com/cryptography@metzdowd.com/msg10142.html|author= Nakamoto, Satoshi |date=9 January 2009 |title=Bitcoin v0.1 released |archiveurl=http://archive.is/KBoi |archivedate=2012-09-04 |deadurl=no}}</ref><ref>{{cite web |url=http://sourceforge.net/news/?group_id=244765 |title=SourceForge.net: Bitcoin |archiveurl=http://archive.is/jC5M |archivedate=2012-07-16 |deadurl=no}}</ref>
** 2009-01-03 - "Satoshi Nakamoto" mines the first block of bitcoins ever (known as the "genesis block"), which had a reward of 50 bitcoins.
* '''2010'''
** The prices for the first bitcoin transactions were negotiated by individuals on the bitcointalk forums. One notable transaction involved a 10,000 BTC pizza.<ref name=Wired:RFB>{{cite web|author=Wallace, Benjamin|title=The Rise and Fall of Bitcoin|url=http://www.wired.com/magazine/2011/11/mf_bitcoin/|publisher=Wired|date=23 November 2011|accessdate=13 October 2012 |archiveurl=http://archive.is/oODpb |archivedate=2013-02-09 |deadurl=no}}</ref>
** On 6 August, a major vulnerability in the Bitcoin protocol was spotted. Transactions weren't properly verified before they were included in the transaction log or "block chain" which allowed for users to bypass Bitcoin's economic restrictions and create an indefinite number of bitcoins.<ref name=Monetarism1 /><ref name=NIST1 />
** On 15 August, the major vulnerability was exploited. Over 184 billion bitcoins were generated in a transaction, and sent to two addresses on the network. Within hours, the transaction was spotted<ref name=SourceForge>{{cite web|author=Nakamoto, Satoshi |title=ALERT - we are investigating a problem|url=http://sourceforge.net/p/bitcoin/mailman/bitcoin-list/?viewmonth=201008|accessdate=15 October 2013}}</ref><ref name=BitcoinTalk>{{cite web|author=Garzik, Jeff |title=Strange block 74638 |url=https://bitcointalk.org/index.php?topic=822.msg9519#msg9519|accessdate=15 October 2013}}</ref> and erased from the transaction log after the bug was fixed and the network forked to an updated version of the Bitcoin protocol. This was the only major security flaw found and exploited in Bitcoin's history.<ref name=Monetarism1>{{cite web|last=Sawyer|first=Matt|title=The Beginners Guide To Bitcoin&nbsp;– Everything You Need To Know|url=http://www.monetarism.co.uk/the-beginners-guide-to-bitcoin-everything-you-need-to-know/|publisher=Monetarism|date=26 February 2013 |archiveurl=http://archive.is/3JU4w |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=NIST1>{{cite web|title=Vulnerability Summary for CVE-2010-5139|url=https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2010-5139|publisher=National Vulnerability Database|accessdate=22 March 2013|date=8 June 2012 |archiveurl=http://archive.is/mgLGp |archivedate=2013-04-09 |deadurl=no}}</ref>
* '''2011–2012'''
** In June 2011, [[Wikileaks]]<ref>{{cite news |last= Greenberg |first= Andy |url= http://blogs.forbes.com/andygreenberg/2011/06/14/wikileaks-asks-for-anonymous-bitcoin-donations/
|title= WikiLeaks Asks For Anonymous Bitcoin Donations |publisher= logs.forbes.com | date= 14 June 2011 |accessdate = 22 June 2011 |archiveurl=http://archive.is/wwVC |archivedate=2012-07-07 |deadurl=no}}</ref> and other organizations began to accept bitcoins for donations. The [[Electronic Frontier Foundation]] temporarily suspended bitcoin acceptance, citing concerns about a lack of legal precedent about new currency systems, and that they "generally don't endorse any type of product or service."<ref>{{cite web |url= https://www.eff.org/deeplinks/2011/06/eff-and-bitcoin |title= EFF and Bitcoin &#124; Electronic Frontier Foundation |publisher= Eff.org |date= 14 June 2011 |accessdate = 22 June 2011 |archiveurl=http://archive.is/sAV7 |archivedate=2012-12-09 |deadurl=no}}</ref> The EFF's decision was changed in 17 May 2013.<ref>{{cite web |url= https://www.eff.org/deeplinks/2013/05/eff-will-accept-bitcoins-support-digital-liberty |title= EFF and Bitcoin &#124; Electronic Frontier Foundation |publisher= Eff.org |date= 17 May 2013 |accessdate = 21 May 2013 |deadurl=no}}</ref>
** In late 2011, the exchange rate of bitcoin crashed from over $30 in June to below $2 in October.
** In January 2012, Bitcoin was featured as the main subject within a fictionalized trial on the [[CBS]] legal drama ''[[The Good Wife]]'' in the third season episode "[[The Good Wife (season 3)#Episodes|Bitcoin for Dummies]]". The host of [[CNBC]]'s ''[[Mad Money]]'', [[Jim Cramer]], played himself in a courtroom scene where he testifies that he doesn’t consider bitcoin a true currency, saying “There’s no central bank to regulate it; it’s digital and functions completely peer to peer.”<ref name="The Good Wife">{{cite web|last=Toepfer|first=Susan|title='The Good Wife' Season 3, Episode 13, 'Bitcoin for Dummies': TV Recap|url=http://blogs.wsj.com/speakeasy/2012/01/16/the-good-wife-season-3-episode-13-bitcoin-for-dummies-tv-recap/|publisher=The Wall Street Journal|date=16 January 2012 |archiveurl=http://archive.is/WyMXp |archivedate=2013-04-12 |deadurl=no}}</ref>
** In October 2012, BitPay reported having over 1,000 merchants accepting Bitcoin under its payment processing service.<ref>{{cite web|title=BitPay Signs 1,000 Merchants to Accept Bitcoin Payments|url=http://www.americanbanker.com/issues/177_176/bitpay-signs-1000-merchants-to-accept-bitcoin-payments-1052538-1.html|publisher=American Banker|date=11 September 2012|author= Browdie, Brian |archiveurl=http://archive.is/BMAA4 |archivedate=2013-01-01 |deadurl=no}}</ref>
* '''2013'''
** February
*** The Bitcoin-based [[payment processor]] [[Coinbase]] reported selling $1 million in bitcoins in a single month at over $22 per bitcoin.<ref name=$1MBitcoinamonth>{{cite web|last=Ludwig|first=Sean|title=Y Combinator-backed Coinbase now selling over $1M Bitcoin per month|url=http://venturebeat.com/2013/02/08/coinbase-bitcoin/|publisher=VentureBeat|date=8 February 2013 |archiveurl=http://archive.is/3sXNi |archivedate=2013-04-12 |deadurl=no}}</ref>
*** The [[Internet Archive]] announced that it is ready to accept donations as bitcoins and that it intends to give employees the option to receive portions of their salaries in Bitcoin currency.<ref name=paritynews>{{cite web|last=Mandalia|first=Ravi|title=The Internet Archive Starts Accepting Bitcoin Donations|url=http://www.paritynews.com/web-news/item/690-the-internet-archive-starts-accepting-bitcoin-donations|publisher=Parity News|date=22 February 2013|accessdate=28 February 2013 |archiveurl=http://archive.is/GQE64 |archivedate=2013-04-11 |deadurl=no}}</ref>
** March
*** The Bitcoin transaction log or "block chain" temporarily forked into two independent logs with differing rules on how transactions could be accepted. The Mt.Gox exchange briefly halted Bitcoin deposits and the exchange rate briefly dipped by 23% to $37 as the event occurred<ref name=ArsFork /><ref name=VergeFork /> before recovering to previous level of approximately $48 in the following hours.<ref>{{cite web|title=Bitcoin Charts|url=http://bitcoincharts.com/charts/mtgoxUSD#rg60zczsg2013-03-12zeg2013-03-15ztgSzm1g10zm2g25zv |archiveurl=http://archive.is/0QOAS |archivedate=2013-04-19 |deadurl=no}}</ref>
*** In the [[United States of America|US]], the [[FinCEN|Financial Crimes Enforcement Network (FinCEN)]] established regulatory guidelines for "decentralized virtual currencies" such as Bitcoin, classifying American "Bitcoin miners" who sell their generated bitcoins as Money Service Businesses (or MSBs), that may be subject to registration and other legal obligations.<ref name=ArsFinCEN /><ref name=Finextra1 /><ref name=FinCEN1 />
** April
*** Payment processor BitInstant and [[Mt.Gox]] experienced processing delays due to insufficient capacity.<ref>Roose, Kevin (8 April 2013) {{cite web |url=http://nymag.com/daily/intelligencer/2013/04/inside-the-bitcoin-bubble-bitinstants-ceo.html |title=Inside the Bitcoin Bubble: BitInstant's CEO&nbsp;– Daily Intelligencer |archiveurl=http://archive.is/yAyxl |archivedate=2013-04-29 |deadurl=no}}. Nymag.com. Retrieved on 20 April 2013.</ref>
*** On 10 April, the bitcoin exchange rate dropped from $266 to $76 before returning to $160 within six hours.<ref>{{cite web|url=http://bitcoincharts.com/charts/mtgoxUSD|title=Bitcoin Exchange Rate|publisher=Bitcoinscharts.com|accessdate=2013-08-15}}</ref>
*** Bitcoin gained greater recognition when services such as [[OkCupid]] and [[Foodler]] began accepting it for payment.<ref>{{cite web|author=Van Sack, Jessica|date=27 May 2013|title=Why Bitcoin makes cents|url=http://bostonherald.com/business/media_marketing/2013/05/why_bitcoin_makes_cents|accessdate=2013-08-15}}</ref>
** May
*** On 15 May 2013, the US authorities seized accounts associated with [[Mt. Gox]] after discovering that it had not registered as a money transmitter with FinCEN in the US.<ref>{{cite web|last=Dillet|first=Romain|title=Feds Seize Assets From Mt. Gox's Dwolla Account, Accuse It Of Violating Money Transfer Regulations|url=http://techcrunch.com/2013/05/16/mt-gox-dwolla-account-money-seizure/|accessdate=2013-05-15}}</ref><ref name="ABA FINCEN">{{cite web
|title=Some basic rules for using ‘bitcoin’ as virtual money |url=http://www.abajournal.com/magazine/article/some_basic_rules_for_using_bitcoin_as_virtual_money/?utm_source=maestro&utm_medium=email&utm_campaign=tech_monthly |publisher=Amercan Bar Association |year=2013 |accessdate=2013-06-26 |last=Berson |first=Susan A.}}</ref>
*** The US-based bitcoin company [[Coinbase]] announces a $5 million [[Series A]] investment, the largest funding round for a bitcoin company.<ref>{{cite web |author=Sarah Needleman |date=May 7, 2013 |url=http://blogs.wsj.com/venturecapital/2013/05/07/coinbase-nabs-5m-in-biggest-funding-for-bitcoin-startup/ |title=Coinbase Nabs $5M in Biggest Funding for Bitcoin Startup}}</ref>
** June
*** On 23 June 2013, it was reported <ref>{{cite web|last=Cohen|first=Brian|title=Users Bitcoins Seized by DEA|url=http://letstalkbitcoin.com/users-bitcoins-seized-by-dea/|accessdate=2013-10-14}}</ref> that the US [[Drug Enforcement Administration]] listed 11.02 bitcoins as a seized asset in a [[United States Department of Justice]] seizure notice pursuant to 21 U.S.C. § 881. It is the first time a government agency has claimed to have seized bitcoin.<ref>{{cite web|publisher=El Cuerpo Nacional de Policía|title=The National Police completes the second phase of the operation "Ransomware"|url=http://translate.google.com/translate?sl=es&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.policia.es%2Fprensa%2F20130927_1.html|accessdate=2013-10-14}}</ref><ref>{{cite web
|title=U.S. government makes its first-ever Bitcoin seizure|url=http://www.dailydot.com/business/11-bitcoins-seized-government-dea/ |publisher=The Daily Dot |year=2013 |accessdate=2013-10-15 |last=Sampson |first=Tim}}</ref>
** July
*** A project under way in Kenya is linking Bitcoin with [[M-Pesa]], a popular mobile payments system, in an experiment designed to spur innovative payments in Africa.<ref>{{cite web|author=Jeremy Kirk |date=July 11, 2013 |title=In Kenya, Bitcoin linked to popular mobile payment system |url=http://www.cio.com/article/736202/In_Kenya_Bitcoin_linked_to_popular_mobile_payment_system|publisher=Cio.com|accessdate=2013-08-15}}</ref>
*** July 30, 2013—The Foreign Exchange Administration and Policy Department in Thailand stated that Bitcoin lacks any legal framework and would therefore be illegal, which effectively banned trading on Bitcoin exchanges in the country.<ref name="telegraph20130730">{{cite news | url=http://www.telegraph.co.uk/finance/currency/10210022/Bitcoins-banned-in-Thailand.html | title=Virtual currency Bitcoin not welcome in Thailand in possible setback to mainstream ambitions | work=[[The Daily Telegraph]] | date=30 July 2013 | accessdate=15 August 2013 | author=Andrew Trotman }}</ref><ref name="investvine">{{cite web|url=http://investvine.com/thailand-first-country-to-ban-digital-currency-bitcoin/|title=Thailand first country to ban digital currency Bitcoin|first=Arno|last=Maierbrugger|work=Inside Investor|date=30 July 2013|accessdate=3 August 2013}}</ref> According to Vitalik Buterin, a writer for Bitcoin Magazine, "Bitcoin’s fate in Thailand may give the electronic currency more credibility in some circles." But he was concerned it didn’t bode well for Bitcoin in China.<ref name="Thailand 2013">{{cite web|title=Virtual currency Bitcoin not welcome in Thailand in possible setback to mainstream ambitions|url=http://www.washingtonpost.com/business/virtual-currency-bitcoin-not-welcome-in-thailand-in-possible-setback-to-mainstream-ambitions/2013/07/30/6bf52bce-f8ea-11e2-a954-358d90d5d72d_story.html|publisher=Washington Post|accessdate=July 31, 2013|date=30 July 2013}}</ref>
*** As of July 2013, BitPay handled bitcoin transactions for more than 4,500 companies.<ref name="Thailand 2013" />
** August
*** Federal Judge Amos Mazzant of the [[Eastern District of Texas]] of the [[Fifth Circuit]] ruled that bitcoins are "a currency or a form of money" (specifically securities as defined by Federal Securities Laws), and as such were subject to the court's jurisdiction.<ref>{{cite web|last=Farivar |first=Cyrus |url=http://arstechnica.com/tech-policy/2013/08/federal-judge-bitcoin-a-currency-can-be-regulated-under-american-law/ |title=Federal judge: Bitcoin, "a currency," can be regulated under American law |publisher=Ars Technica |date=2013-08-07 |accessdate=2013-08-15}}</ref> The case, brought by the U.S. Securities and Exchange Commission, is ongoing.<ref>{{cite web|title=Securities and Exchange Commission v. Shavers et al, 4:13-cv-00416 (E.D.Tex.)|url=https://www.docketalarm.com/cases/Texas_Eastern_District_Court/4--13-cv-00416/Securities_and_Exchange_Commission_v._Shavers_et_al/|publisher=Docket Alarm, Inc.|accessdate=14 August 2013}}</ref>
*** Germany's Finance Ministry subsumed Bitcoins under the term "unit of account"—a financial instrument—though not as e-money or a functional currency, a classification nonetheless having legal and tax implications.<ref name=Marketwatch20130819>{{cite web |url=http://blogs.marketwatch.com/thetell/2013/08/19/bitcoins-are-private-money-in-germany/ |title=Bitcoins are private money in Germany |last=Vaishampayan |first=Saumya |date=August 19, 2013 |website=[[Marketwatch]] |archiveurl=http://www.webcitation.org/6JJIqfMJn |archivedate=September 1, 2013 }}</ref>
**October
*** The FBI seized roughly 26,000 BTC from [[Silk Road (marketplace)|Silk Road]].<ref>{{cite web|title=After Silk Road seizure, FBI Bitcoin wallet identified and pranked|url=http://www.zdnet.com/after-silk-road-seizure-fbi-bitcoin-wallet-identified-and-pranked-7000021603/}}</ref><ref>{{cite web|url=http://blockchain.info/address/1F1tAaz5x1HUXrCNLbtMDqcw6o5GNn4xqX|title=Silkroad Seized Coins}}</ref><ref>http://www.forbes.com/sites/kashmirhill/2013/10/04/fbi-silk-road-bitcoin-seizure/</ref>
***Two companies, [[Robocoin]] and [[Bitcoiniacs]] announce that the world's first Bitcoin [[ATM]] will launch October 29 in [[Vancouver]], [[BC]], [[Canada]], allowing clients to sell or purchase Bitcoin currency at a downtown coffee shop.<ref>{{cite web|url= http://www.cbc.ca/news/business/world-s-first-bitcoin-atm-goes-live-in-vancouver-next-week-1.2251820/ |publisher= [[CBC]]}}</ref><ref>{{cite web|url=http://www.vancouversun.com/technology/personal-tech/Vancouver+host+world+first+Bitcoin/9084958/story.html|title=Vancouver to host world’s first Bitcoin ATM}}</ref>


===Satoshi Nakamoto===
===Satoshi Nakamoto===
Satoshi Nakamoto is a pseudonym for the unknown person or people who designed the original Bitcoin protocol in 2008 and launched the network in 2009. Nakamoto was responsible for creating the majority of the Bitcoin software and was active in making modifications and posting technical information on the BitcoinTalk Forum.<ref name=autogenerated2>{{cite web|title=The Rise and Fall of Bitcoin |url= http://www.wired.com/magazine/2011/11/mf_bitcoin/ |publisher= [[Wired (website)|Wired]] |date=23 November 2011|accessdate= 13 October 2012 |archiveurl=http://archive.is/oODpb |archivedate=2013-02-09 |deadurl=no}}</ref>
Satoshi Nakamoto is a pseudonym for the unknown person or people who designed the original Bitcoin protocol in 2008 and launched the network in 2009. Nakamoto was responsible for creating the majority of the Bitcoin software and was active in making modifications and posting technical information on the BitcoinTalk Forum.<ref name=autogenerated2>{{cite web|title=The Rise and Fall of Bitcoin |url= http://www.wired.com/magazine/2011/11/mf_bitcoin/ |publisher= [[Wired (website)|Wired]] |date=23 November 2011|accessdate= 13 October 2012 |archiveurl=http://archive.is/oODpb |archivedate=2013-02-09 |deadurl=no}}</ref>


Investigations into the real [[wikt:identity|identity]] of Satoshi Nakamoto have been attempted by ''[[The New Yorker]]'' and ''[[Fast Company (magazine)|Fast Company]]''. ''Fast Company'''s investigation brought up [[circumstantial evidence]] linking an [[encryption]] [[patent]] application filed by Neal King, Vladimir Oksman and Charles Bry on 15 August 2008, and the bitcoin.org domain name which was registered 72 hours later. The patent application ([http://patent.ipexl.com/U2S/20100042841.html #20100042841]) contained networking and encryption technologies similar to Bitcoin's, and [[Content analysis|textual analysis]] revealed that the phrase "...computationally impractical to reverse" appeared in both the patent application and bitcoin's whitepaper. All three inventors explicitly denied being Satoshi Nakamoto.<ref>{{cite web|last= Penenberg |first= Adam |title= The Bitcoin Crypto-Currency Mystery Reopened |url= http://www.fastcompany.com/1785445/bitcoin-crypto-currency-mystery-reopened |publisher= [[FastCompany]] |accessdate= 16 February 2013 |archiveurl=http://archive.is/97HqS |archivedate=2013-04-09 |deadurl=no}}</ref><ref>{{cite web|last= Greenfield |first= Rebecca |title= The Race to Unmask Bitcoin's Inventor(s) |url= http://www.theatlanticwire.com/technology/2011/10/race-unmask-bitcoins-inventors/43535/ |publisher= [[The Atlantic]] |date=11 October 2011|accessdate= 16 February 2013 |archiveurl=http://archive.is/RHThA |archivedate=2013-04-12 |deadurl=no}}</ref>
Investigations into the real [[wikt:identity|identity]] of Satoshi Nakamoto have been attempted by ''[[The New Yorker]]'' and ''[[Fast Company (magazine)|Fast Company]]''. ''Fast Company'''s investigation brought up [[circumstantial evidence]] linking an [[encryption]] [[patent]] application filed by Neal King, Vladimir Oksman and Charles Bry on 15 August 2008, and the bitcoin.org domain name which was registered 72 hours later. The patent application ([http://patent.ipexl.com/U2S/20100042841.html #20100042841]) contained networking and encryption technologies similar to Bitcoin's, and [[Content analysis|textual analysis]] revealed that the phrase "...computationally impractical to reverse" appeared in both the patent application and bitcoin's whitepaper.<ref name=whitepaper /> All three inventors explicitly denied being Satoshi Nakamoto.<ref>{{cite web|last= Penenberg |first= Adam |title= The Bitcoin Crypto-Currency Mystery Reopened |url= http://www.fastcompany.com/1785445/bitcoin-crypto-currency-mystery-reopened |publisher= [[FastCompany]] |accessdate= 16 February 2013 |archiveurl=http://archive.is/97HqS |archivedate=2013-04-09 |deadurl=no}}</ref><ref>{{cite web|last= Greenfield |first= Rebecca |title= The Race to Unmask Bitcoin's Inventor(s) |url= http://www.theatlanticwire.com/technology/2011/10/race-unmask-bitcoins-inventors/43535/ |publisher= [[The Atlantic]] |date=11 October 2011|accessdate= 16 February 2013 |archiveurl=http://archive.is/RHThA |archivedate=2013-04-12 |deadurl=no}}</ref>
In May 2013, [[Ted Nelson]] speculated that Japanese mathematician [[Shinichi Mochizuki]] is Satoshi Nakamoto.<ref>{{cite web|date= 18 May 2013 |url= https://www.youtube.com/watch?v=emDJTGTrEm0 |title= I Think I Know Who Satoshi Is |publisher= YouTube TheTedNelson Channel}}</ref>
In May 2013, [[Ted Nelson]] speculated that Japanese mathematician [[Shinichi Mochizuki]] is Satoshi Nakamoto.<ref>{{cite web|date= 18 May 2013 |url= https://www.youtube.com/watch?v=emDJTGTrEm0 |title= I Think I Know Who Satoshi Is |publisher= YouTube TheTedNelson Channel}}</ref>


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Developers at bitcoin.org resolved the split by recommending that users downgrade to "version 0.7", which utilized the oldest transaction log in the split. User funds largely remained unaffected and were available when network consensus was reached.<ref name=ChainFork1>{{cite web|title=11/12 March 2013 Chain Fork Information|url=http://bitcoin.org/chainfork.html|publisher=Bitcoin Project|accessdate=12 March 2013 |archiveurl=http://archive.is/Fo4tS |archivedate=2013-04-14 |deadurl=no}}</ref> The network reached consensus and continued to operate as normal a few hours after the split.<ref>{{cite web|title=Bitcoin software bug has been rapidly resolved|url=http://ecurrency.ec/2013/03/bitcoin-bug-resolved/|publisher=ecurrency|date=12 March 2013 |archiveurl=http://archive.is/cyTYJ |archivedate=2013-04-12 |deadurl=no}}</ref>
Developers at bitcoin.org resolved the split by recommending that users downgrade to "version 0.7", which utilized the oldest transaction log in the split. User funds largely remained unaffected and were available when network consensus was reached.<ref name=ChainFork1>{{cite web|title=11/12 March 2013 Chain Fork Information|url=http://bitcoin.org/chainfork.html|publisher=Bitcoin Project|accessdate=12 March 2013 |archiveurl=http://archive.is/Fo4tS |archivedate=2013-04-14 |deadurl=no}}</ref> The network reached consensus and continued to operate as normal a few hours after the split.<ref>{{cite web|title=Bitcoin software bug has been rapidly resolved|url=http://ecurrency.ec/2013/03/bitcoin-bug-resolved/|publisher=ecurrency|date=12 March 2013 |archiveurl=http://archive.is/cyTYJ |archivedate=2013-04-12 |deadurl=no}}</ref>


===2013 Bitcoin prices===
===Regulatory issues===
On 18 March 2013, the [[Financial Crimes Enforcement Network]] (or FinCEN), a bureau of the [[United States Department of the Treasury]], issued a report regarding [[centralized]] and decentralized "virtual currencies" and their legal status within "[[money services business]]" (MSB) and [[Bank Secrecy Act]] regulations.<ref name=FinCEN1 /><ref name="ABA FINCEN" /> It classified digital currencies and other digital payment systems such as Bitcoin as "virtual currencies" because they are not [[legal tender]] under any sovereign [[jurisdiction (area)|jurisdiction]]. FinCEN cleared American users of Bitcoin of legal obligations<ref name="ABA FINCEN" /> by saying, "A user of virtual currency is not an MSB under FinCEN’s regulations and therefore is not subject to MSB registration, reporting, and recordkeeping regulations." However, it held that American entities who generate "virtual currency" such as bitcoins are money transmitters or MSBs if they sell their generated currency for [[national currency]]: "...a person that creates units of convertible virtual currency and sells those units to another person for real currency or its equivalent is engaged in transmission to another location and is a money transmitter." This specifically extends to "miners" of the Bitcoin currency who may have to register as MSBs and abide by the legal requirements of being a money transmitter if they sell their generated bitcoins for [[national currency]] and are within the [[United States]].<ref name=ArsFinCEN>{{cite web|last=Lee|first=Timothy|title=US regulator Bitcoin Exchanges Must Comply With Money Laundering Laws|url=http://arstechnica.com/tech-policy/2013/03/us-regulator-bitcoin-exchanges-must-comply-with-money-laundering-laws/|publisher=Arstechnica|date=20 March 2013|quote=Bitcoin miners must also register if they trade in their earnings for dollars. |archiveurl=http://archive.is/ozDCh |archivedate=2013-04-07 |deadurl=no}}</ref>

Additionally, FinCEN claimed regulation over American entities that manage bitcoins in a [[payment processor]] setting or as an exchanger: "In addition, a person is an exchanger and a money transmitter if the person accepts such de-centralized convertible virtual currency from one person and transmits it to another person as part of the acceptance and transfer of currency, funds, or other value that substitutes for currency."<ref name=Finextra1>{{cite web|title=US govt clarifies virtual currency regulatory position|url=http://www.finextra.com/News/FullStory.aspx?newsitemid=24645|publisher=Finextra|date=19 March 2013 |archiveurl=http://archive.is/W176A |archivedate=2013-04-09 |deadurl=no}}</ref><ref name=FinCEN1>{{cite web|title=Application of FinCEN's Regulations to Persons Administering, Exchanging, or Using Virtual Currencies|url=http://www.fincen.gov/statutes_regs/guidance/pdf/FIN-2013-G001.pdf|publisher=Department of the Treasury Financial Crimes Enforcement Network|accessdate=19 March 2013}}</ref>

In summary, FinCEN's decision would require Bitcoin exchanges where bitcoins are traded for traditional currencies to disclose large transactions and suspicious activity, comply with [[money laundering]] regulations, and collect information about their customers as traditional [[financial institutions]] are required to do.<ref name="ABA FINCEN" /><ref name=Forbes1>{{cite web|last=Lee|first=Timothy|title=New Money Laundering Guidelines Are A Positive Sign For Bitcoin|url=http://www.forbes.com/sites/timothylee/2013/03/19/new-money-laundering-guidelines-are-a-positive-sign-for-bitcoin/|publisher=Forbes|date=19 March 2013 |archiveurl=http://archive.is/dlI9t |archivedate=2013-04-10 |deadurl=no}}</ref><ref name=JapanTimes>{{cite web|title=The rise of the bitcoin: Virtual gold or cyber-bubble?|url=http://articles.washingtonpost.com/2013-04-04/world/38280106_1_bitcoin-satoshi-nakamoto-monetary-policy|publisher=Washington Post|date=4 April 2013 |archiveurl=http://archive.is/pWxnr |archivedate=2013-04-29 |deadurl=no}}</ref>

Patrick Murck of the Bitcoin Foundation criticized FinCEN's report as an "overreach" and claimed that FinCEN "cannot rely on this guidance in any enforcement action".<ref name=BTCFoundationFinCEN1>{{cite web|last=Murck|first=Patrick|title=Today, we are all money transmitters... (no, really!)|url=https://bitcoinfoundation.org/blog/?p=152|publisher=Bitcoin Foundation|date=19 March 2013 |archiveurl=http://archive.is/eWcYH |archivedate=2013-04-14 |deadurl=no}}</ref>{{primary source-inline|date=June 2013}}

[[Jennifer Shasky Calvery]], the director of FinCEN said, “Virtual currencies are subject to the same rules as other currencies. … Basic money-services business rules apply here.”<ref name="ABA FINCEN" />

In its October 2012 study, ''Virtual currency schemes'', the [[European Central Bank]] concluded that the growth of virtual currencies will continue, and, given the currencies' inherent price instability, lack of close regulation, and risk of illegal uses by anonymous users, the Bank warned that periodic examination of developments would be necessary to reassess risks.<ref name=ECBank201210>{{cite web |url=http://www.ecb.int/pub/pdf/other/virtualcurrencyschemes201210en.pdf |title=Virtual Currency Schemes |last= |first= |date=October 2012 |publisher=European Central Bank |archiveurl=http://www.webcitation.org/6IQmm0QiP |archivedate=July 27, 2013 }}</ref>

In 2013, the U.S. Treasury extended its anti-money laundering regulations to processors of bitcoin transactions.<ref name="foxnews1">{{cite web |url=http://www.foxnews.com/tech/2013/04/11/bitcoin-electronic-cash-beloved-by-hackers/ |title=Bitcoin, the nationless electronic cash beloved by hackers, bursts into financial mainstream |archiveurl=http://archive.is/YwB03 |archivedate=2013-04-29 |deadurl=no}}. Fox News (11 April 2013). Retrieved on 20 April 2013.</ref><ref>{{cite web |url=http://blog.aarp.org/2013/04/11/bitcoin-currency-hackers-make-money-investing-in-bitcoins-scams/ |title=Bitcoin Currency, Hackers Make Money, Investing in Bitcoins, Scams&nbsp;– AARP |archiveurl=http://archive.is/98mWj |archivedate=2013-04-29 |deadurl=no}}. Blog.aarp.org (19 March 2013). Retrieved on 20 April 2013.</ref>

In June 2013, Bitcoin Foundation board member Jon Matonis wrote in ''Forbes'' that he received a warning letter from California's Department of Financial Institutions accusing the foundation of unlicensed money transmission, Matonis denying the foundation is engaged in money transmission and saying he viewed the case as "an opportunity to educate state regulators."<ref name=NBCnews20130624>{{cite web |url=http://www.nbcnews.com/technology/bitcoin-losing-shine-after-hitting-spotlight-6C10066339 |title=Bitcoin losing shine after hitting the spotlight |last=Coldewey |first=Devin |date=June 24, 2013 |publisher=NBC News |archiveurl=http://www.webcitation.org/6IQjnlc52 |archivedate=July 27, 2013 }}</ref>

In late July 2013, the industry group Committee for the Establishment of the Digital Asset Transfer Authority began to form to set best practices and standards, to work with regulators and policymakers to adapt existing currency requirements to digital currency technology and business models and develop risk management standards.<ref name=WashPost20130730>{{cite web |url=http://www.washingtonpost.com/business/technology/bitcoin-industry-leaders-set-up-standards-group/2013/07/30/8ce4d73c-f94c-11e2-afc1-c850c6ee5af8_story.html |title=Bitcoin, others set up standards group |last=Tsukayama |first= Hayley |date=July 30, 2013 |website=The Washington Post |archiveurl=http://www.webcitation.org/6IXzf8vD2 |archivedate=August 1, 2013 }}</ref>

===2013 bitcoin prices===
[[File:BitstampUSD weekly.png|thumb|450px|The bitcoin to USD exchange rates at one of the exchanges]]
[[File:BitstampUSD weekly.png|thumb|450px|The bitcoin to USD exchange rates at one of the exchanges]]
The price of a bitcoin reached an all-time high of US$230 on 9 April 2013, up from just $13 at the start of the year.<ref name="quandl">{{cite web|url=http://www.quandl.com/BITCOIN/MTGOXUSD |title=Bitcoin Markets (mtgoxUSD) – Bitcoin Charts |publisher=Quandl |date= |accessdate=2013-08-15}}</ref> Among the factors which may have contributed to this rise were the [[European sovereign-debt crisis]]—particularly the [[2012–2013 Cypriot financial crisis]]—statements by FinCEN improving the currency's legal standing and rising media and Internet interest.<ref name=NewYorker1>{{cite web|last=Traverse|first=Nick|title=Bitcoin's Meteoric Rise|url=http://www.newyorker.com/online/blogs/newsdesk/2013/04/the-number-141.html|date=3 April 2013 |archiveurl=http://archive.is/gfRcQ |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=NewYorker2>{{cite web|last=Bustillos|first=Maria|title=The Bitcoin Boom|url=http://www.newyorker.com/online/blogs/elements/2013/04/the-future-of-bitcoin.html|date=2 April 2013 |archiveurl=http://archive.is/s4wpw |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=Quartz1>{{cite web|last=Seward|first=Zachary|title=Bitcoin, up 152% this month, soaring 57% this week|url=http://qz.com/68328/bitcoin-up-152-this-month-tops-1-billion-in-total-value/|accessdate=9 April 2013|date=28 March 2013 |archiveurl=http://archive.is/u9QqU |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=Economist1>{{cite news|title=A Bit expensive|url=http://www.economist.com/blogs/graphicdetail/2013/03/daily-chart-12|date=1 March 2013 |archiveurl=http://archive.is/xfasi |archivedate=2013-04-29 |deadurl=no}}</ref>
The price of a bitcoin reached an all-time high of US$230 on 9 April 2013, up from just $13 at the start of the year.<ref name="quandl">{{cite web|url=http://www.quandl.com/BITCOIN/MTGOXUSD |title=Bitcoin Markets (mtgoxUSD) – Bitcoin Charts |publisher=Quandl |date= |accessdate=2013-08-15}}</ref> Among the factors which may have contributed to this rise were the [[European sovereign-debt crisis]]—particularly the [[2012–2013 Cypriot financial crisis]]—statements by FinCEN improving the currency's legal standing and rising media and Internet interest.<ref name=NewYorker1>{{cite web|last=Traverse|first=Nick|title=Bitcoin's Meteoric Rise|url=http://www.newyorker.com/online/blogs/newsdesk/2013/04/the-number-141.html|date=3 April 2013 |archiveurl=http://archive.is/gfRcQ |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=NewYorker2>{{cite web|last=Bustillos|first=Maria|title=The Bitcoin Boom|url=http://www.newyorker.com/online/blogs/elements/2013/04/the-future-of-bitcoin.html|date=2 April 2013 |archiveurl=http://archive.is/s4wpw |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=Quartz1>{{cite web|last=Seward|first=Zachary|title=Bitcoin, up 152% this month, soaring 57% this week|url=http://qz.com/68328/bitcoin-up-152-this-month-tops-1-billion-in-total-value/|accessdate=9 April 2013|date=28 March 2013 |archiveurl=http://archive.is/u9QqU |archivedate=2013-04-29 |deadurl=no}}</ref><ref name=Economist1>{{cite news|title=A Bit expensive|url=http://www.economist.com/blogs/graphicdetail/2013/03/daily-chart-12|date=1 March 2013 |archiveurl=http://archive.is/xfasi |archivedate=2013-04-29 |deadurl=no}}</ref>
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==Economics==
==Economics==
Large fluctuations in the value of Bitcoin have led to criticism of its usefulness as a currency.<ref name=Guardian77>{{cite web|last=Moore|first=Heidi|title=Confused about Bitcoin? It's 'the Harlem Shake of currency'|url=http://www.guardian.co.uk/commentisfree/2013/apr/03/bitcoin-currency-bubble-crash-not-rocking-financial-markets|publisher=The Guardian|accessdate=8 April 2013 |archiveurl=http://archive.is/FhJtu |archivedate=2013-04-29 |deadurl=no}}</ref> In addition, its deflationary bias encourages [[Hoarding (economics)|hoarding]].<ref>For ''The Atlantic'' article, see {{cite web|last=O'Brien|first=Matthew|title=Bitcoin Is No Longer a Currency|url=http://www.theatlantic.com/business/archive/2013/04/bitcoin-is-no-longer-a-currency/274859/|publisher=The Atlantic|date=11 April 2013 |archiveurl=http://archive.is/Hm3uS |archivedate=2013-04-29 |deadurl=no}}</ref> This reduces the use value of a currency and has been the downfall of other private currencies.<ref>{{cite web | url=http://www.slate.com/articles/news_and_politics/view_from_chicago/2013/04/bitcoin_is_a_ponzi_scheme_the_internet_currency_will_collapse.html | title=Fool's Gold: Bitcoin is a Ponzi scheme—the Internet’s favorite currency will collapse. | publisher=The Slate Group | work=slate.com | date=April 11 2013 | accessdate=26 October 2013 | author=Posner, Eric}}</ref> However, currently Bitcoin does see some use as a currency<ref>{{cite web |url=http://www.guardian.co.uk/business/2013/mar/04/bitcoin-currency-of-vice |title=Bitcoin: more than just the currency of digital vice Technology guardian.co.uk |archiveurl=http://archive.is/kRH7B |archivedate=2013-04-29 |deadurl=no}}. Guardian (4 March 2013). Retrieved on 20 April 2013.</ref> as well as being horded by individuals.<ref>Popper, Nathaniel. (13 December 2012) {{cite web |url=http://dealbook.nytimes.com/2013/04/11/as-big-investors-emerge-bitcoin-gets-ready-for-its-close-up/ |title=Never Mind Facebook; Winklevoss Twins Rule in Digital Money |archiveurl=http://archive.is/85HVC |archivedate=2013-04-29 |deadurl=no}}. Dealbook.nytimes.com. Retrieved on 20 April 2013.</ref>
Large fluctuations in the value of Bitcoin have led to criticism of its usefulness as a currency.<ref name=Guardian77>{{cite web|last=Moore|first=Heidi|title=Confused about Bitcoin? It's 'the Harlem Shake of currency'|url=http://www.guardian.co.uk/commentisfree/2013/apr/03/bitcoin-currency-bubble-crash-not-rocking-financial-markets|publisher=The Guardian|accessdate=8 April 2013 |archiveurl=http://archive.is/FhJtu |archivedate=2013-04-29 |deadurl=no}}</ref> In addition, its deflationary bias encourages [[Hoarding (economics)|hoarding]].<ref>For ''The Atlantic'' article, see {{cite web|last=O'Brien|first=Matthew|title=Bitcoin Is No Longer a Currency|url=http://www.theatlantic.com/business/archive/2013/04/bitcoin-is-no-longer-a-currency/274859/|publisher=The Atlantic|date=11 April 2013 |archiveurl=http://archive.is/Hm3uS |archivedate=2013-04-29 |deadurl=no}}</ref> This reduces the use value of a currency and has been the downfall of other private currencies.<ref>{{cite web | url=http://www.slate.com/articles/news_and_politics/view_from_chicago/2013/04/bitcoin_is_a_ponzi_scheme_the_internet_currency_will_collapse.html | title=Fool's Gold: Bitcoin is a Ponzi scheme—the Internet’s favorite currency will collapse. | publisher=The Slate Group | work=slate.com | date=April 11, 2013 | accessdate=26 October 2013 | author=Posner, Eric}}</ref> However, currently Bitcoin does see some use as a currency<ref>{{cite web |url=http://www.guardian.co.uk/business/2013/mar/04/bitcoin-currency-of-vice |title=Bitcoin: more than just the currency of digital vice Technology guardian.co.uk |archiveurl=http://archive.is/kRH7B |archivedate=2013-04-29 |deadurl=no}}. Guardian (4 March 2013). Retrieved on 20 April 2013.</ref> as well as being horded by individuals.<ref>Popper, Nathaniel. (13 December 2012) {{cite web |url=http://dealbook.nytimes.com/2013/04/11/as-big-investors-emerge-bitcoin-gets-ready-for-its-close-up/ |title=Never Mind Facebook; Winklevoss Twins Rule in Digital Money |archiveurl=http://archive.is/85HVC |archivedate=2013-04-29 |deadurl=no}}. Dealbook.nytimes.com. Retrieved on 20 April 2013.</ref>

===Exchanges===
Through various [[:Category: Bitcoin exchanges|exchanges]], bitcoins are bought and sold at a variable price against the value of other currency. Bitcoin has appreciated rapidly in relation to other currencies including the [[US dollar]], [[euro]] and [[British pound]].<ref name="quandl" /><ref>{{cite web|url=http://www.quandl.com/BITCOIN/MTGOXEUR |title=Bitcoin Markets (mtgoxEUR) – Bitcoin Charts |publisher=Quandl |date= |accessdate=2013-08-15}}</ref><ref>{{cite web|url=http://www.quandl.com/BITCOIN/MTGOXGBP |title=Bitcoin Markets (mtgoxGBP) – Bitcoin Charts |publisher=Quandl |date= |accessdate=2013-08-15}}</ref>

Bitcoin exchanges regularly fail, and the vast majority of transactions are completed on a single exchange that was originally a site for trading Magic: The Gathering cards online, Mt. Gox.

According to [[Reuters]], undisclosed documents indicate that [[bank]]s such as [[Morgan Stanley]] and [[Goldman Sachs]] have visited Bitcoin exchanges as often as 30 times a day. Employees of international banks and major financial organizations have shown interest in Bitcoin markets as well.<ref name=Reuters1>{{cite web|last=O'Leary|first=Naomi|title=Bitcoin, the City traders' anarchic new toy|url=http://www.reuters.com/article/2012/04/01/traders-bitcoin-idUSL6E8ET5K620120401|publisher=Reuters|date=1 April 2012|quote=Workers at Morgan Stanley and Goldman Sachs in London and New York have been visiting online Bitcoin exchanges as often as 30 times a day, according to documents seen by Reuters. Neither bank wanted to comment. Employees at almost all the major international banks and numerous trading and investment firms have shown interest. |archiveurl=http://archive.is/52sM |archivedate=2012-09-09 |deadurl=no}}</ref>


===Bitcoin as an investment===
===Bitcoin as an investment===
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===Bitcoin bubble===
===Bitcoin bubble===
Many have mentioned speculative [[bubble (economics)|bubbles]] in connection with Bitcoin, and Reuters journalist Felix Salmon correctly predicted the bursting of one such Bitcoin bubble in April of 2013.<ref>For Salmon's April 3rd prediction, see {{cite web | url=https://medium.com/money-banking/2b5ef79482cb | title=The Bitcoin Bubble and the Future of Currency | work=medium.com | date=April 3, 2013 | accessdate=26 October 2013 | author=Salmon, Felix}}
Many have mentioned speculative [[bubble (economics)|bubbles]] in connection with Bitcoin, and Reuters journalist Felix Salmon correctly predicted the bursting of one such Bitcoin bubble in April 2013.<ref>For Salmon's April 3rd prediction, see {{cite web | url=https://medium.com/money-banking/2b5ef79482cb | title=The Bitcoin Bubble and the Future of Currency | work=medium.com | date=April 3, 2013 | accessdate=26 October 2013 | author=Salmon, Felix}}
*For bubble bursting April 12th, see {{cite web | url=http://money.cnn.com/2013/04/12/investing/bitcoin-bubble/ | title=Bitcoin bubble may have burst | publisher=CNN | work=CNNMoney | date=April 12, 2013 | accessdate=26 October 2013 | author=Isidore, Chris}}</ref>
*For bubble bursting April 12th, see {{cite web | url=http://money.cnn.com/2013/04/12/investing/bitcoin-bubble/ | title=Bitcoin bubble may have burst | publisher=CNN | work=CNNMoney | date=April 12, 2013 | accessdate=26 October 2013 | author=Isidore, Chris}}</ref>


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Some have suggested that hording Bitcoins will become a popular activity for individuals living in countries with problem plagued local currencies and that it can be used to circumvent capital controls and international sanctions.
Some have suggested that hording Bitcoins will become a popular activity for individuals living in countries with problem plagued local currencies and that it can be used to circumvent capital controls and international sanctions.


Bitcoins are used to some extent by Argentinians an as an alternative to the official currency,<ref>{{cite web |url=http://blogs.ft.com/beyond-brics/2013/04/16/bitcoins-gain-traction-in-argentina/ |title=Bitcoins gain traction in Argentina |archiveurl=http://archive.is/LxHxE |archivedate=2013-04-29 |deadurl=no}}. Blogs.ft.com (16 April 2013). Retrieved on 20 April 2013.</ref> which is stymied by inflation and strict capital controls.<ref name=WashPost20130821/>
Bitcoins are used to some extent by Argentinians an as an alternative to the official currency,<ref>{{cite web |url=http://blogs.ft.com/beyond-brics/2013/04/16/bitcoins-gain-traction-in-argentina/ |title=Bitcoins gain traction in Argentina |archiveurl=http://archive.is/LxHxE |archivedate=2013-04-29 |deadurl=no}}. Blogs.ft.com (16 April 2013). Retrieved on 20 April 2013.</ref> which is stymied by inflation and strict capital controls.<ref name=WashPost20130821/>


Some Iranians use Bitcoins to evade currency sanctions.<ref>{{cite journal|last=Raskin|first=Max|title=Dollar-Less Iranians Discover Virtual Currency|journal=BloombergBusinessWeek|date=29 November 2012|url=http://www.businessweek.com/articles/2012-11-29/dollar-less-iranians-discover-virtual-currency|accessdate=15 April 2013 |archiveurl=http://archive.is/ncmdv |archivedate=2013-04-17 |deadurl=no}}</ref>
Some Iranians use Bitcoins to evade currency sanctions.<ref>{{cite journal|last=Raskin|first=Max|title=Dollar-Less Iranians Discover Virtual Currency|journal=BloombergBusinessWeek|date=29 November 2012|url=http://www.businessweek.com/articles/2012-11-29/dollar-less-iranians-discover-virtual-currency|accessdate=15 April 2013 |archiveurl=http://archive.is/ncmdv |archivedate=2013-04-17 |deadurl=no}}</ref>


Financial journalists and analysts have speculated that there was a correlation between higher bitcoin usage in [[Spain]] and the [[2012–2013 Cypriot financial crisis]], and that bitcoin is serving as a sort of financial haven for some European savers.<ref name=BloombergCyprus>{{cite web|last=Salyer|first=Kirsten|title=Fleeing the Euro for Bitcoins|url=http://www.bloomberg.com/news/2013-03-20/fleeing-the-euro-for-bitcoins-.html|publisher=Bloomberg L.P.|date=21 March 2013 |archiveurl=http://archive.is/TJbl6 |archivedate=2013-04-10 |deadurl=no}}</ref>
Financial journalists and analysts have speculated that there was a correlation between higher bitcoin usage in [[Spain]] and the [[2012–2013 Cypriot financial crisis]] that bitcoin is serving as a sort of financial haven for some European savers.<ref name=BloombergCyprus>{{cite web|last=Salyer|first=Kirsten|title=Fleeing the Euro for Bitcoins|url=http://www.bloomberg.com/news/2013-03-20/fleeing-the-euro-for-bitcoins-.html|publisher=Bloomberg L.P.|date=21 March 2013 |archiveurl=http://archive.is/TJbl6 |archivedate=2013-04-10 |deadurl=no}}</ref>


==Implications==
===Academic research and mention by Economists===
There is little scholarship in the area of virtual currency such as Bitcoin, and most economists that have commented on Bitcoin have been critical.


===Privacy===
Economist [[Paul Krugman]] has been critical of Bitcoin, suggesting that the structure of the currency incentives hoarding<ref name=Krugman1>{{cite web|last=Krugman|first=Paul|title=Golden Cyberfetters|url=http://krugman.blogs.nytimes.com/2011/09/07/golden-cyberfetters/|publisher=New York Times|date=7 September 2011 |archiveurl=http://archive.is/jzUoz |archivedate=2013-04-11 |deadurl=no}}</ref> and also stating its value from the expectation that others will accept it as payment.<ref>{{cite news|last=Krugman|first=Paul|title=The Antisocial Network|url=http://www.nytimes.com/2013/04/15/opinion/krugman-the-antisocial-network.html|newspaper=New York Times|date=14 April 2013 |archiveurl=http://archive.is/jdAYc |archivedate=2013-04-29 |deadurl=no}}</ref> Krugman considers it wasteful to spend real resources, such as electric power, on the creation of Bitcoins.<ref>{{cite news|last=Krugman|first=Paul|title=Adam Smith Hates Bitcoin|url=http://krugman.blogs.nytimes.com/2013/04/12/adam-smith-hates-bitcoin/|newspaper=New York Times|date=12 April 2013 |archiveurl=http://archive.is/TAgyQ |archivedate=2013-04-29 |deadurl=no}}</ref>
Bitcoin transactions are seen as relatively anonymous.<ref name=economist>{{cite news |url=http://www.economist.com/node/21563752 |title=Monetarists Anonymous |archiveurl=http://archive.is/j6sDZ |archivedate=2013-01-02 |deadurl=no}}. The Economist (29 September 2012). Accessed 1 April 2013.</ref> Bitcoins were the medium of exchange used in the online [[black market]] website [[Silk Road (marketplace)|Silk Road]].<ref name="Forbes">Greenberg, Andy (20 April 2011). {{cite web |url=http://www.forbes.com/forbes/2011/0509/technology-psilocybin-bitcoins-gavin-andresen-crypto-currency.html |title=Crypto Currency |archiveurl=http://archive.is/KDAp |archivedate=2012-12-08 |deadurl=no}}. Forbes Magazine.</ref><ref>{{cite web |last= Madrigal |first= Alexis |title= Libertarian Dream? A Site Where You Buy Drugs With Digital Dollars |publisher= [[The Atlantic Monthly]] |date= 1 June 2011 |url= http://www.theatlantic.com/technology/archive/2011/06/libertarian-dream-a-site-where-you-buy-drugs-with-digital-dollars/239776/ |accessdate = 5 June 2011 |archiveurl=http://archive.is/INs7 |archivedate=2012-12-09 |deadurl=no}}</ref> Some Bitcoin proponents are concerned that such associations may bring about negative perceptions of the currency.<ref>Chen, Adrian (1 June 2011). {{cite web |url=http://gawker.com/5805928/the-underground-website-where-you-can-buy-any-drug-imaginable |title=The Underground Website Where You Can Buy Any Drug Imaginable |archiveurl=http://archive.is/hQa2 |archivedate=2012-07-26 |deadurl=no}}. Gawker.</ref>


The privacy of Bitcoin is the subject of active academic research.<ref>Androulaki, Elli ''et al.'' (2012) [http://eprint.iacr.org/2012/596.pdf Evaluating User Privacy in Bitcoin]. eprint.iacr.org</ref> Because Bitcoin transactions are broadcast to the entire network, they are inherently public. Using external information, it is possible, though usually difficult, to associate Bitcoin identities with real-life identities<ref name="An Analysis of Anonymity in the Bitcoin System">Fergal Reid and Martin Harrigan (24 July 2011). {{cite web |url=http://anonymity-in-bitcoin.blogspot.com/2011/07/bitcoin-is-not-anonymous.html |title=An Analysis of Anonymity in the Bitcoin System |archiveurl=http://archive.is/7IPTk |archivedate=2013-04-14 |deadurl=no}}. An Analysis of Anonymity in the Bitcoin System.</ref><ref>The Economist. {{cite news |url=http://www.economist.com/node/21563752 |title=Monetarists Anonymous |archiveurl=http://archive.is/j6sDZ |archivedate=2013-01-02 |deadurl=no}}. 29 September 2012. Accessed 1 April 2013.</ref> through analysis of past Bitcoin transactions to reveal patterns that can unmask user identities.<ref name=WashPost20130821>{{cite web |url=http://www.washingtonpost.com/blogs/the-switch/wp/2013/08/21/five-surprising-facts-about-bitcoin-2/ |title=Five surprising facts about Bitcoin |last=Lee |first=Timothy B. |date=August 19, 2013 |website=The Washington Post |archiveurl=http://www.webcitation.org/6J4o6F0yO |archivedate=August 22, 2013 }} • Brito, Jerry, and Castillo, Andrea, (2013). ''[http://mercatus.org/sites/default/files/Brito_BitcoinPrimer.pdf A Primer for Policymakers].'' [[Mercatus Center]].</ref> Unlike regular banking,<ref>{{cite web |url= http://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cash/0 |title= Bitcoin: The Cryptoanarchists' Answer to Cash |publisher= IEEE.org |date= June 2012 |accessdate = 5 June 2012 |archiveurl=http://archive.is/75DuQ |archivedate=2013-01-13 |deadurl=no}}</ref> which can preserve customer privacy by keeping transaction records private, loose transactional privacy is accomplished in Bitcoin by using many unique addresses for every wallet even though all transactions are published. However, according to the [[Mercatus Center]]'s ''Primer for Policymakers'' (2013), after Bitcoin intermediaries comply with the same bank secrecy regulations required of traditional financial intermediaries, anonymity will be less protected because Bitcoin intermediaries will be required to collect personal customer data.<ref name=WashPost20130821/>
[[Larry Summers]] has expressed a "wait and see" attitude when it comes to Bitcoins.<ref>{{cite web | url=http://www.technologyreview.com/news/427348/larry-summers-and-the-technology-of-money/page/2/ | title=Larry Summers and the Technology of Money | publisher=MIT | work=MIT Technology Review | date=March 28, 2012 | accessdate=27 October 2013 | author=Myhrvold, Conor}}</ref>


An [[IEEE]] paper proposes a cryptographic extension to Bitcoin called [[Zerocoin]], which would make Bitcoin anonymous and untraceable.<ref>Miers, Ian. [http://spar.isi.jhu.edu/~mgreen/ZerocoinOakland.pdf Zerocoin: Anonymous Distributed E-Cash from Bitcoin]. isi.jhu.edu</ref><ref>{{cite web |url=http://blog.cryptographyengineering.com/2013/04/zerocoin-making-bitcoin-anonymous.html |title=A Few Thoughts on Cryptographic Engineering: Zerocoin: making Bitcoin anonymous |archiveurl=http://archive.is/wkZfe |archivedate=2013-04-29 |deadurl=no}}. Blog.cryptographyengineering.com (11 April 2013). Retrieved on 20 April 2013.</ref><ref>[http://www.forbes.com/sites/andygreenberg/2013/04/12/zerocoin-add-on-for-bitcoin-could-make-it-truly-anonymous-and-untraceable/ 'Zerocoin' Add-on For Bitcoin Could Make It Truly Anonymous And Untraceable], Forbes, 26-05-2013</ref><ref>[http://zerocoin.org/ zerocoin.org], 26-05-2013</ref><ref>[http://www.newbitcoinworld.com/2013/04/this-is-huge-gold-20-can-code-and.html This is Huge: Gold 2.0 – Can code and competition build a better Bitcoin?], New Bitcoin World, 26-05-2013</ref>
Numerous economists including [[John Quiggin]] and [[Steve Hanke]] have mentioned the possibility of a Bitcoin bubble.<ref>For Quiggin, see {{cite news|url=http://nationalinterest.org/commentary/the-bitcoin-bubble-bad-hypothesis-8353|title=The Bitcoin Bubble and a Bad Hypothesis|last=Quiggin|first=John|work=The National Interest|date=16 April 2013 |archiveurl=http://archive.is/IQVny |archivedate=2013-04-29 |deadurl=no}}
*For Hanke, see {{cite web | url=http://www.gq-magazine.co.uk/comment/articles/2013-04/05/bitcoin-bubble-exchange-rate-crash | title=When the Bitcoin Bubble will burst | publisher=Conde Naste | work=gq-magazine.co.uk | date=05 April 13 | accessdate=27 October 2013 | author=Franklin, Oliver}}</ref>


===Criminal activities===
Research on Bitcoins has been conducted by the ConvergEx Group and an assistant professor at Carnegie Mellon, Nicholas Christin.<ref>For ConvergEx Group, see {{cite web|last=Boesler|first=Matthew|title=ANALYST: The Rise Of Bitcoin Teaches A Tremendous Lesson About Global Economics|url=http://www.businessinsider.com/global-economics-lesson-from-bitcoin-2013-3|publisher=Business Insider|date=7 March 2013 |archiveurl=http://archive.is/YqHXP |archivedate=2013-04-10 |deadurl=no}}
Bitcoins have acquired a reputation for use by criminals to purchase drugs, launder money, and gamble. While there is some merit to these claims, as of 2013 Bitcoins do not appear to be extensively used in money laundering. Gambling with Bitcoins is popular and accounts for a large percentage of Bitcoin transactions (although a smaller percentage of transactions by value), and a significant proportion of Bitcoin activity can be linked to the purchase of illegal drugs.
*For research by Nicholas Christin, see {{cite web | url=http://www.andrew.cmu.edu/user/nicolasc/ | title=Nicolas Christin: Carnegie Mellon University Assistant Research Professo | publisher=cmu.edu | work=Carnegie Mellon University | accessdate=27 October 2013}}</ref>


Named a "shady online currency [that] is starting to gain legitimacy in certain parts of the world" by CNN,<ref name=cnn>{{cite web | url=http://finance.fortune.cnn.com/2012/12/18/bitcoin-money-laundering/ | title=Bitcoin looks primed for money laundering | publisher=CNN | work=money.cnn.com | date=December 18, 2012 | accessdate=18 October 2013 | author=Sanati, Cyrus}}</ref> ''[[The Washington Post]]'' has labelled it "the currency of choice for seedy online activities."<ref name=washp>{{cite web | url=http://articles.washingtonpost.com/2013-10-02/business/42613812_1_digital-currency-federal-authorities-reputation | title=Authorities shut down Silk Road, the world’s largest Bitcoin-based drug market | work=The Washington Post | date=October 2, 2013 | accessdate=21 October 2013 | author=Timothy B. Lee and Hayley Tsukayama}}</ref> The FBI stated in a 2012 report that "Bitcoins will likely continue to attract cybercriminals who view it as a means to move or steal funds".<ref name="fbi_report"/> Steven Strauss, a Harvard public policy professor, suggested in 2013 that "if Bitcoins facilitate too much drug-dealing or money laundering, the U.S. government could make their possession illegal."<ref>{{cite web | url=http://www.huffingtonpost.com/steven-strauss/bitcoin_b_3081812.html | title=Nine Trust-Based Problems With Bitcoin | publisher=TheHuffingtonPost.com, Inc | work=huffingtonpost.com | date=04/14/201 | accessdate=20 October 2013 | author=Strauss, Steven}}</ref> A 2013 [[U.S. Securities and Exchange Commission|SEC]] filing made by a Bitcoin investment vehicle also mentioned the possibility that Bitcoins would become illegal.<ref name=toomanyspecs/>
==Privacy==
Bitcoin transactions are seen as relatively anonymous.<ref name=economist>{{cite news |url=http://www.economist.com/node/21563752 |title=Monetarists Anonymous |archiveurl=http://archive.is/j6sDZ |archivedate=2013-01-02 |deadurl=no}}. The Economist (29 September 2012). Accessed 1 April 2013.</ref> Bitcoins were the medium of exchange used in the online [[black market]] website [[Silk Road (marketplace)|Silk Road]].<ref name="Forbes">Greenberg, Andy (20 April 2011). {{cite web |url=http://www.forbes.com/forbes/2011/0509/technology-psilocybin-bitcoins-gavin-andresen-crypto-currency.html |title=Crypto Currency |archiveurl=http://archive.is/KDAp |archivedate=2012-12-08 |deadurl=no}}. Forbes Magazine.</ref><ref>{{cite web |last= Madrigal |first= Alexis |title= Libertarian Dream? A Site Where You Buy Drugs With Digital Dollars |publisher= [[The Atlantic Monthly]] |date= 1 June 2011 |url= http://www.theatlantic.com/technology/archive/2011/06/libertarian-dream-a-site-where-you-buy-drugs-with-digital-dollars/239776/ |accessdate = 5 June 2011 |archiveurl=http://archive.is/INs7 |archivedate=2012-12-09 |deadurl=no}}</ref> Some Bitcoin proponents are concerned that such associations may bring about negative perceptions of the currency.<ref>Chen, Adrian (1 June 2011). {{cite web |url=http://gawker.com/5805928/the-underground-website-where-you-can-buy-any-drug-imaginable |title=The Underground Website Where You Can Buy Any Drug Imaginable |archiveurl=http://archive.is/hQa2 |archivedate=2012-07-26 |deadurl=no}}. Gawker.</ref>


In 2013 ''[[The Guardian]]'' reported that the currency was primarily used to purchase illegal drugs and for online gambling,<ref name=mainly>{{cite web | url=http://www.theguardian.com/world/2013/mar/22/silk-road-online-drug-marketplace | title=Silk Road: the online drug marketplace that officials seem powerless to stop | publisher=Guardian News and Media Limited | work=theguardian.com | date=22 March 2013 | accessdate=20 October 2013 | author=Ball, James}}</ref> and ''[[The Huffington Post]]'' stated that "online gambling accounts for a huge portion of Bitcoin activity."<ref>{{cite web | url=http://www.huffingtonpost.co.uk/tommy-wyher/bitcoin_b_4125434.html | title=The Rise and Rise of Bitcoin | publisher=Thehuffingtonpost.com, Inc. | work=The Huffington Post | date=2013-10-19 | accessdate=21 October 2013 | author=Wyher, Tommy}}</ref> Legitimate transactions are thought to be far less than the number involved in the purchase of drugs,<ref>{{cite web | url=http://www.forbes.com/sites/quora/2013/10/02/how-will-the-fbi-shut-down-of-silk-road-affect-bitcoins/ | title=How Will The FBI Shut Down Of Silk Road Affect Bitcoins? | publisher=Forbes | work=Quora | date=10/02/201 | accessdate=21 October 2013 | author=John Jeffrey Mardlin}}</ref> and roughly one half of all transactions made using Bitcoins are bets placed at a single online gaming website.<ref>{{cite web | url=http://arstechnica.com/business/2013/08/firm-says-online-gambling-accounts-for-almost-half-of-all-bitcoin-transactions/ | title=Firm says online gambling accounts for almost half of all Bitcoin transactions | publisher=Conte Naste | work=Ars Technica | date=Aug 24 2013 | accessdate=21 October 2013 | author=Geuss, Megan}}</ref> In 2012, an academic from the Carnegie Mellon CyLab and the Information Networking Institute estimated that 4.5 to 9% of all Bitcoins spent were for purchases of drugs at a single online market, Silk Road.<ref name=cmacademic>{{cite conference | url=http://www.andrew.cmu.edu/user/nicolasc/publications/Christin-WWW13.pdf | title=Traveling the Silk Road: A Measurement Analysis of a Large Anonymous Online Marketplace | publisher=Carnegie Mellon INI/CyLab | accessdate=22 October 2013 | author=Christin, Nicolas | year=2013 | pages=8}}</ref> However, as the majority of the Bitcoin transactions were at this time speculative in nature, this academic asserts that drugs constituted a much larger percentage of the products and services bought using Bitcoins.<ref name=cmacademic/>
The privacy of Bitcoin is the subject of active academic research.<ref>Androulaki, Elli ''et al.'' (2012) [http://eprint.iacr.org/2012/596.pdf Evaluating User Privacy in Bitcoin]. eprint.iacr.org</ref> Because Bitcoin transactions are broadcast to the entire network, they are inherently public. Using external information, it is possible, though usually difficult, to associate Bitcoin identities with real-life identities<ref name="An Analysis of Anonymity in the Bitcoin System">Fergal Reid and Martin Harrigan (24 July 2011). {{cite web |url=http://anonymity-in-bitcoin.blogspot.com/2011/07/bitcoin-is-not-anonymous.html |title=An Analysis of Anonymity in the Bitcoin System |archiveurl=http://archive.is/7IPTk |archivedate=2013-04-14 |deadurl=no}}. An Analysis of Anonymity in the Bitcoin System.</ref><ref>The Economist. {{cite news |url=http://www.economist.com/node/21563752 |title=Monetarists Anonymous |archiveurl=http://archive.is/j6sDZ |archivedate=2013-01-02 |deadurl=no}}. 29 September 2012. Accessed 1 April 2013.</ref> through analysis of past Bitcoin transactions to reveal patterns that can unmask user identities.<ref name=WashPost20130821>{{cite web |url=http://www.washingtonpost.com/blogs/the-switch/wp/2013/08/21/five-surprising-facts-about-bitcoin-2/ |title=Five surprising facts about Bitcoin |last=Lee |first=Timothy B. |date=August 19, 2013 |website=The Washington Post |archiveurl=http://www.webcitation.org/6J4o6F0yO |archivedate=August 22, 2013 }} • Brito, Jerry, and Castillo, Andrea, (2013). ''[http://mercatus.org/sites/default/files/Brito_BitcoinPrimer.pdf A Primer for Policymakers].'' [[Mercatus Center]].</ref> Unlike regular banking,<ref>{{cite web |url= http://spectrum.ieee.org/computing/software/bitcoin-the-cryptoanarchists-answer-to-cash/0 |title= Bitcoin: The Cryptoanarchists' Answer to Cash |publisher= IEEE.org |date= June 2012 |accessdate = 5 June 2012 |archiveurl=http://archive.is/75DuQ |archivedate=2013-01-13 |deadurl=no}}</ref> which can preserve customer privacy by keeping transaction records private, loose transactional privacy is accomplished in Bitcoin by using many unique addresses for every wallet even though all transactions are published. However, according to the [[Mercatus Center]]'s ''Primer for Policymakers'' (2013), after Bitcoin intermediaries comply with the same bank secrecy regulations required of traditional financial intermediaries, anonymity will be less protected because Bitcoin intermediaries will be required to collect personal customer data.<ref name=WashPost20130821/>


Several news outlets assert that the popularity of Bitcoins hinges on the ability to use them to purchase illegal substances.<ref name=econ/> In addition to such utility, Bitcoins are thought by the FBI as a potential tool of money launderers,<ref name=fbi_report/> and ''The Huffington Post'' stated in 2013 that Bitcoins are the "preferred currency of some online gun dealers," which allows the purchase of arms without background checks.<ref>{{cite web | url=http://www.huffingtonpost.com/2013/04/15/bitcoin-guns_n_3070828.html | title=How Bitcoin Sales Of Guns Could Undermine New Rules | publisher=TheHuffingtonPost.com, Inc. | work=huffingtonpost.com | date=2013-04-15 | accessdate=20 October 2013 | author=Smith, Gerry}}</ref> Such links to illicit activity have attracted the attention of financial regulators, legislative bodies, and law enforcement.<ref>{{cite web | url=http://www.bloomberg.com/news/2013-08-08/did-the-sec-just-validate-bitcoin-no-.html | title=The SEC Shows Why Bitcoin Is Doomed | publisher=Bloomberg LP | work=bloomberg.com | date=Aug 8, 2013 | accessdate=20 October 2013 | author=Lavin, Tim}}</ref>
An [[IEEE]] paper proposes a cryptographic extension to Bitcoin called [[Zerocoin]], which would make Bitcoin anonymous and untraceable.<ref>Miers, Ian. [http://spar.isi.jhu.edu/~mgreen/ZerocoinOakland.pdf Zerocoin: Anonymous Distributed E-Cash from Bitcoin]. isi.jhu.edu</ref><ref>{{cite web |url=http://blog.cryptographyengineering.com/2013/04/zerocoin-making-bitcoin-anonymous.html |title=A Few Thoughts on Cryptographic Engineering: Zerocoin: making Bitcoin anonymous |archiveurl=http://archive.is/wkZfe |archivedate=2013-04-29 |deadurl=no}}. Blog.cryptographyengineering.com (11 April 2013). Retrieved on 20 April 2013.</ref><ref>[http://www.forbes.com/sites/andygreenberg/2013/04/12/zerocoin-add-on-for-bitcoin-could-make-it-truly-anonymous-and-untraceable/ 'Zerocoin' Add-on For Bitcoin Could Make It Truly Anonymous And Untraceable], Forbes, 26-05-2013</ref><ref>[http://zerocoin.org/ zerocoin.org], 26-05-2013</ref><ref>[http://www.newbitcoinworld.com/2013/04/this-is-huge-gold-20-can-code-and.html This is Huge: Gold 2.0 – Can code and competition build a better Bitcoin?], New Bitcoin World, 26-05-2013</ref>


Although there are fears that Bitcoins may be used to launder money, the FBI stated in 2012 that, while the potential for money laundering exists, there were no known instances of this occurring.<ref name=fbi_report>{{cite web | url=http://cryptome.org/2012/05/fbi-bitcoin.pdf | title=Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity | publisher=FBI | work=Cyber Intelligence Section and Criminal Intelligence Section | date=24 April 2012 | accessdate=20 October 2013}}</ref> However, in 2013 US authorities seized assets belonging to Mt. Gox, a service that allowed users to exchange Bitcoins for US dollars.<ref>{{cite web | url=http://gawker.com/feds-seize-assets-of-worlds-largest-bitcoin-exchange-506790294 | title=Feds Seize Assets of World's Largest Bitcoin Exchange | publisher=Gawker Media | work=gawker.com | date=2013-05-15 | accessdate=20 October 2013 | author=Chen, Adrian}}</ref> Some say one obstacle to Bitcoins becoming widely used to launder money may be the fact that transaction history is public although the individuals themselves are thought to remain anonymous.<ref name=FistfulPaper201308>{{cite web |url=http://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf |title=A Fistful of Bitcoins: Characterizing Payments Among Men with No Names |last=Meiklejohn |first=Sarah ''et al.'' |date=October 23, 2013 (formal publication) |publisher=Association for Computing Machinery (ACM) |archiveurl= |archivedate=September __, 2013 }} • Paper is explained by {{cite web |url=http://www.pcworld.com/article/2047608/bitcoin-offers-privacy-as-long-as-you-dont-cash-out-or-spend-it.html |title=Bitcoin offers privacy—as long as you don't cash out or spend it |last=Kirk |first=Jeremy |date=August 28, 2013 |website=PC World |archiveurl= |archivedate=September __, 2013 }}</ref>
==Energy use and environmental impact==

===Energy use and environmental impact===
An April 2013 estimate showed that the amount of electricity being used every day to mine bitcoins was about 982 megawatt hours, the amount capable of powering about 31,000 American homes.<ref>{{Cite news|title=Virtual Bitcoin Mining Is a Real-World Environmental Disaster |url= http://www.bloomberg.com/news/2013-04-12/virtual-bitcoin-mining-is-a-real-world-environmental-disaster.html | date=Apr 12 2013 |publisher=[[Bloomberg L.P.|Bloomberg]] | accessdate=Apr 19 2013 |archiveurl=http://archive.is/EGhkM |archivedate=2013-04-29 |deadurl=no}}</ref> This was estimated to be about USD $147,000 worth of energy. In comparison, profits made from a day's worth of bitcoin mining were given at about $681,000.
An April 2013 estimate showed that the amount of electricity being used every day to mine bitcoins was about 982 megawatt hours, the amount capable of powering about 31,000 American homes.<ref>{{Cite news|title=Virtual Bitcoin Mining Is a Real-World Environmental Disaster |url= http://www.bloomberg.com/news/2013-04-12/virtual-bitcoin-mining-is-a-real-world-environmental-disaster.html | date=Apr 12 2013 |publisher=[[Bloomberg L.P.|Bloomberg]] | accessdate=Apr 19 2013 |archiveurl=http://archive.is/EGhkM |archivedate=2013-04-29 |deadurl=no}}</ref> This was estimated to be about USD $147,000 worth of energy. In comparison, profits made from a day's worth of bitcoin mining were given at about $681,000.

===Botnet mining===
In June 2011, [[Symantec]] warned about the possibility of [[botnet]]s engaging in covert mining of bitcoins,<ref>{{cite web|author=Peter Coogan |url=http://www.symantec.com/connect/blogs/bitcoin-botnet-mining |title=Bitcoin Botnet Mining |work=Symantec.com |date=17 June 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/uusZ |archivedate=2012-09-14 |deadurl=no}}</ref><ref>{{cite web|url=http://www.zdnet.com/blog/security/researchers-find-malware-rigged-with-bitcoin-miner/8934 |title=Researchers find malware rigged with Bitcoin miner |publisher=ZDNet |date=29 June 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/7Uhft |archivedate=2013-01-05 |deadurl=no}}</ref> consuming computing cycles, using extra electricity and possibly increasing the temperature of the computer. Some malware also used the [[parallel computing|parallel processing]] capabilities of the [[GPU]]s built into many modern-day [[video card]]s.<ref>{{Cite news |url=http://www.theregister.co.uk/2011/08/16/gpu_bitcoin_brute_forcing/ |title=Malware mints virtual currency using victim's GPU |date=16 August 2011|first=Dan |last=Goodin |archiveurl=http://archive.is/oDCb |archivedate=2012-12-23 |deadurl=no}}</ref>


Later that month, the [[Australian Broadcasting Corporation]] caught an employee using the company's servers to generate Bitcoins without permission.<ref>{{cite web|url=http://thenextweb.com/au/2011/06/23/abc-employee-caught-mining-for-bitcoins-on-company-servers/ |title=ABC employee caught mining for Bitcoins on company servers |publisher=The Next Web |date=23 June 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/JwrjC |archivedate=2013-01-05 |deadurl=no}}</ref>
Later that month, the [[Australian Broadcasting Corporation]] caught an employee using the company's servers to generate Bitcoins without permission.<ref>{{cite web|url=http://thenextweb.com/au/2011/06/23/abc-employee-caught-mining-for-bitcoins-on-company-servers/ |title=ABC employee caught mining for Bitcoins on company servers |publisher=The Next Web |date=23 June 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/JwrjC |archivedate=2013-01-05 |deadurl=no}}</ref>
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In mid-August 2011, Bitcoin miner botnets were detected again,<ref>{{cite web|url=http://www.infosecurity-magazine.com/view/20211/researcher-discovers-distributed-bitcoin-cracking-trojan-malware/ |title=Infosecurity&nbsp;– Researcher discovers distributed bitcoin cracking trojan malware |publisher=Infosecurity-magazine.com |date=19 August 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/TliPM |archivedate=2013-01-03 |deadurl=no}}</ref> and less than three months later bitcoin-mining trojans infecting Mac OS X were also discovered.<ref>{{cite web|url=http://www.techworld.com.au/article/405849/mac_os_x_trojan_steals_processing_power_produce_bitcoins |title=Mac OS X Trojan steals processing power to produce Bitcoins&nbsp;– sophos, security, malware, Intego&nbsp;– Vulnerabilities&nbsp;– Security |publisher=Techworld |date=1 November 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/SDT4 |archivedate=2012-09-18 |deadurl=no}}</ref>
In mid-August 2011, Bitcoin miner botnets were detected again,<ref>{{cite web|url=http://www.infosecurity-magazine.com/view/20211/researcher-discovers-distributed-bitcoin-cracking-trojan-malware/ |title=Infosecurity&nbsp;– Researcher discovers distributed bitcoin cracking trojan malware |publisher=Infosecurity-magazine.com |date=19 August 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/TliPM |archivedate=2013-01-03 |deadurl=no}}</ref> and less than three months later bitcoin-mining trojans infecting Mac OS X were also discovered.<ref>{{cite web|url=http://www.techworld.com.au/article/405849/mac_os_x_trojan_steals_processing_power_produce_bitcoins |title=Mac OS X Trojan steals processing power to produce Bitcoins&nbsp;– sophos, security, malware, Intego&nbsp;– Vulnerabilities&nbsp;– Security |publisher=Techworld |date=1 November 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/SDT4 |archivedate=2012-09-18 |deadurl=no}}</ref>


==Theft and technical vulnerabilities==
===Theft and technical vulnerabilities===
There have been incidents of theft of bitcoin balances:
There have been incidents of theft of bitcoin balances:
* On 19 June 2011, a security breach of the [[Mt.Gox]] bitcoin exchange caused the nominal price of a bitcoin to fraudulently drop to one cent on the Mt.Gox exchange, after a hacker allegedly used credentials from a Mt.Gox auditor's compromised computer illegally to transfer a large number of bitcoins to himself. He used the exchange's software to sell them all nominally, creating a massive "ask" order at any price. Within minutes the price corrected to its correct user-traded value.<ref>{{cite web|last= Karpeles |first= Mark |title= Clarification of Mt Gox Compromised Accounts and Major Bitcoin Sell-Off |date= 30 June 2011 |url= https://mtgox.com/press_release_20110630.html |publisher= Tibanne Co. Ltd. |archiveurl=http://archive.is/2DHQ |archivedate=2012-12-08 |deadurl=no}}</ref><ref>{{cite web|date= 19 June 2011 |url= http://www.youtube.com/watch?v=T1X6qQt9ONg |title= Bitcoin Report Volume 8&nbsp;– (FLASHCRASH) |publisher= YouTube BitcoinChannel}}</ref><ref name="mick">{{cite web|last= Mick |first= Jason |title= Inside the Mega-Hack of Bitcoin: the Full Story |date= 19 June 2011 |url= http://www.dailytech.com/Inside+the+MegaHack+of+Bitcoin+the+Full+Story/article21942.htm |publisher= [[DailyTech]] |archiveurl=http://archive.is/fsllb |archivedate=2013-01-02 |deadurl=no}}</ref><ref>Lee, Timothy B. (19 June 2011) {{cite web |url=http://arstechnica.com/tech-policy/news/2011/06/bitcoin-price-plummets-on-compromised-exchange.ars |title=Bitcoin prices plummet on hacked exchange |archiveurl=http://archive.is/Oa40 |archivedate=2012-07-09 |deadurl=no}}, Ars Technica</ref><ref>Karpeles, Mark (20 June 2011) [https://support.mtgox.com/entries/20208066-huge-bitcoin-sell-off-due-to-a-compromised-account-rollback Huge Bitcoin sell off due to a compromised account&nbsp;– rollback], Mt.Gox Support {{Dead link|url=https://support.mtgox.com/entries/20208066-huge-bitcoin-sell-off-due-to-a-compromised-account-rollback|date=April 2013}}</ref><ref name="register1">{{Cite news|title= Bitcoin collapses on malicious trade&nbsp;– Mt Gox scrambling to raise the Titanic |url= http://www.theregister.co.uk/2011/06/19/bitcoin_values_collapse_again/|date=19 June 2011 |author= Chirgwin, Richard |publisher= The Register |archiveurl=http://archive.is/X2SOt |archivedate=2013-01-14 |deadurl=no}}</ref> Accounts with the equivalent of more than 8,750,000 USD were affected.<ref name="mick" />
* On 19 June 2011, a security breach of the [[Mt.Gox]] bitcoin exchange caused the nominal price of a bitcoin to fraudulently drop to one cent on the Mt.Gox exchange, after a hacker allegedly used credentials from a Mt.Gox auditor's compromised computer illegally to transfer a large number of bitcoins to himself. He used the exchange's software to sell them all nominally, creating a massive "ask" order at any price. Within minutes the price corrected to its correct user-traded value.<ref>{{cite web|last= Karpeles |first= Mark |title= Clarification of Mt Gox Compromised Accounts and Major Bitcoin Sell-Off |date= 30 June 2011 |url= https://mtgox.com/press_release_20110630.html |publisher= Tibanne Co. Ltd. |archiveurl=http://archive.is/2DHQ |archivedate=2012-12-08 |deadurl=no}}</ref><ref>{{cite web|date= 19 June 2011 |url= http://www.youtube.com/watch?v=T1X6qQt9ONg |title= Bitcoin Report Volume 8&nbsp;– (FLASHCRASH) |publisher= YouTube BitcoinChannel}}</ref><ref name="mick">{{cite web|last= Mick |first= Jason |title= Inside the Mega-Hack of Bitcoin: the Full Story |date= 19 June 2011 |url= http://www.dailytech.com/Inside+the+MegaHack+of+Bitcoin+the+Full+Story/article21942.htm |publisher= [[DailyTech]] |archiveurl=http://archive.is/fsllb |archivedate=2013-01-02 |deadurl=no}}</ref><ref>Lee, Timothy B. (19 June 2011) {{cite web |url=http://arstechnica.com/tech-policy/news/2011/06/bitcoin-price-plummets-on-compromised-exchange.ars |title=Bitcoin prices plummet on hacked exchange |archiveurl=http://archive.is/Oa40 |archivedate=2012-07-09 |deadurl=no}}, Ars Technica</ref><ref>Karpeles, Mark (20 June 2011) [https://support.mtgox.com/entries/20208066-huge-bitcoin-sell-off-due-to-a-compromised-account-rollback Huge Bitcoin sell off due to a compromised account&nbsp;– rollback], Mt.Gox Support {{Dead link|url=https://support.mtgox.com/entries/20208066-huge-bitcoin-sell-off-due-to-a-compromised-account-rollback|date=April 2013}}</ref><ref name="register1">{{Cite news|title= Bitcoin collapses on malicious trade&nbsp;– Mt Gox scrambling to raise the Titanic |url= http://www.theregister.co.uk/2011/06/19/bitcoin_values_collapse_again/|date=19 June 2011 |author= Chirgwin, Richard |publisher= The Register |archiveurl=http://archive.is/X2SOt |archivedate=2013-01-14 |deadurl=no}}</ref> Accounts with the equivalent of more than 8,750,000 USD were affected.<ref name="mick" />
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* On 11 August 2013, the Bitcoin Foundation announced that a bug in a [[pseudorandom number generator]] within the [[Android (operating system)|Android]] operating system had been exploited to steal from users' wallets, the vulnerability affecting wallets generated by any Android app; fixes were provided 13 August 2013.<ref name=TheRegister20130812>{{cite web |url=http://www.theregister.co.uk/2013/08/12/android_bug_batters_bitcoin_wallets/ |title=Android bug batters Bitcoin wallets / Old flaw, new problem |last=Chirgwin |first=Richard |date=12 August 2013 |website=The Register |archiveurl=http://www.webcitation.org/6IwX8oDIN |archivedate=17 August 2013 }} ● Original Bitcoin announcement: {{cite web |url=http://bitcoin.org/en/alert/2013-08-11-android |title=Android Security Vulnerability |date=11 August 2013 |publisher=bitcoin.org |archiveurl=http://www.webcitation.org/6IwXaL2GC |archivedate=17 August 2013 }}</ref>
* On 11 August 2013, the Bitcoin Foundation announced that a bug in a [[pseudorandom number generator]] within the [[Android (operating system)|Android]] operating system had been exploited to steal from users' wallets, the vulnerability affecting wallets generated by any Android app; fixes were provided 13 August 2013.<ref name=TheRegister20130812>{{cite web |url=http://www.theregister.co.uk/2013/08/12/android_bug_batters_bitcoin_wallets/ |title=Android bug batters Bitcoin wallets / Old flaw, new problem |last=Chirgwin |first=Richard |date=12 August 2013 |website=The Register |archiveurl=http://www.webcitation.org/6IwX8oDIN |archivedate=17 August 2013 }} ● Original Bitcoin announcement: {{cite web |url=http://bitcoin.org/en/alert/2013-08-11-android |title=Android Security Vulnerability |date=11 August 2013 |publisher=bitcoin.org |archiveurl=http://www.webcitation.org/6IwXaL2GC |archivedate=17 August 2013 }}</ref>


===Taxation===

===Regulation and taxation===
On 18 March 2013, the [[Financial Crimes Enforcement Network]] (or FinCEN), a bureau of the [[United States Department of the Treasury]], issued a report regarding [[centralized]] and decentralized "virtual currencies" and their legal status within "[[money services business]]" (MSB) and [[Bank Secrecy Act]] regulations.<ref name=FinCEN1 /><ref name="ABA FINCEN">{{cite web
|title=Some basic rules for using ‘bitcoin’ as virtual money |url=http://www.abajournal.com/magazine/article/some_basic_rules_for_using_bitcoin_as_virtual_money/?utm_source=maestro&utm_medium=email&utm_campaign=tech_monthly |publisher=Amercan Bar Association |year=2013 |accessdate=2013-06-26 |last=Berson |first=Susan A.}}</ref> It classified digital currencies and other digital payment systems such as Bitcoin as "virtual currencies" because they are not [[legal tender]] under any sovereign [[jurisdiction (area)|jurisdiction]]. FinCEN cleared American users of Bitcoin of legal obligations<ref name="ABA FINCEN" /> by saying, "A user of virtual currency is not an MSB under FinCEN’s regulations and therefore is not subject to MSB registration, reporting, and recordkeeping regulations." However, it held that American entities who generate "virtual currency" such as bitcoins are money transmitters or MSBs if they sell their generated currency for [[national currency]]: "...a person that creates units of convertible virtual currency and sells those units to another person for real currency or its equivalent is engaged in transmission to another location and is a money transmitter." This specifically extends to "miners" of the Bitcoin currency who may have to register as MSBs and abide by the legal requirements of being a money transmitter if they sell their generated bitcoins for [[national currency]] and are within the [[United States]].<ref name=ArsFinCEN>{{cite web|last=Lee|first=Timothy|title=US regulator Bitcoin Exchanges Must Comply With Money Laundering Laws|url=http://arstechnica.com/tech-policy/2013/03/us-regulator-bitcoin-exchanges-must-comply-with-money-laundering-laws/|publisher=Arstechnica|date=20 March 2013|quote=Bitcoin miners must also register if they trade in their earnings for dollars. |archiveurl=http://archive.is/ozDCh |archivedate=2013-04-07 |deadurl=no}}</ref>

Additionally, FinCEN claimed regulation over American entities that manage bitcoins in a [[payment processor]] setting or as an exchanger: "In addition, a person is an exchanger and a money transmitter if the person accepts such de-centralized convertible virtual currency from one person and transmits it to another person as part of the acceptance and transfer of currency, funds, or other value that substitutes for currency."<ref name=Finextra1>{{cite web|title=US govt clarifies virtual currency regulatory position|url=http://www.finextra.com/News/FullStory.aspx?newsitemid=24645|publisher=Finextra|date=19 March 2013 |archiveurl=http://archive.is/W176A |archivedate=2013-04-09 |deadurl=no}}</ref><ref name=FinCEN1>{{cite web|title=Application of FinCEN's Regulations to Persons Administering, Exchanging, or Using Virtual Currencies|url=http://www.fincen.gov/statutes_regs/guidance/pdf/FIN-2013-G001.pdf|publisher=Department of the Treasury Financial Crimes Enforcement Network|accessdate=19 March 2013}}</ref>

In summary, FinCEN's decision would require Bitcoin exchanges where bitcoins are traded for traditional currencies to disclose large transactions and suspicious activity, comply with [[money laundering]] regulations, and collect information about their customers as traditional [[financial institutions]] are required to do.<ref name="ABA FINCEN" /><ref name=Forbes1>{{cite web|last=Lee|first=Timothy|title=New Money Laundering Guidelines Are A Positive Sign For Bitcoin|url=http://www.forbes.com/sites/timothylee/2013/03/19/new-money-laundering-guidelines-are-a-positive-sign-for-bitcoin/|publisher=Forbes|date=19 March 2013 |archiveurl=http://archive.is/dlI9t |archivedate=2013-04-10 |deadurl=no}}</ref><ref name=JapanTimes>{{cite web|title=The rise of the bitcoin: Virtual gold or cyber-bubble?|url=http://articles.washingtonpost.com/2013-04-04/world/38280106_1_bitcoin-satoshi-nakamoto-monetary-policy|publisher=Washington Post|date=4 April 2013 |archiveurl=http://archive.is/pWxnr |archivedate=2013-04-29 |deadurl=no}}</ref>

Patrick Murck of the Bitcoin Foundation criticized FinCEN's report as an "overreach" and claimed that FinCEN "cannot rely on this guidance in any enforcement action".<ref name=BTCFoundationFinCEN1>{{cite web|last=Murck|first=Patrick|title=Today, we are all money transmitters... (no, really!)|url=https://bitcoinfoundation.org/blog/?p=152|publisher=Bitcoin Foundation|date=19 March 2013 |archiveurl=http://archive.is/eWcYH |archivedate=2013-04-14 |deadurl=no}}</ref>{{primary source-inline|date=June 2013}}

[[Jennifer Shasky Calvery]], the director of FinCEN said, “Virtual currencies are subject to the same rules as other currencies. … Basic money-services business rules apply here.”<ref name="ABA FINCEN" />

In its October 2012 study, ''Virtual currency schemes'', the [[European Central Bank]] concluded that the growth of virtual currencies will continue, and, given the currencies' inherent price instability, lack of close regulation, and risk of illegal uses by anonymous users, the Bank warned that periodic examination of developments would be necessary to reassess risks.<ref name=ECBank201210>{{cite web |url=http://www.ecb.int/pub/pdf/other/virtualcurrencyschemes201210en.pdf |title=Virtual Currency Schemes |last= |first= |date=October 2012 |publisher=European Central Bank |archiveurl=http://www.webcitation.org/6IQmm0QiP |archivedate=July 27, 2013 }}</ref>

In 2013, the U.S. Treasury extended its anti-money laundering regulations to processors of bitcoin transactions.<ref name="foxnews1">{{cite web |url=http://www.foxnews.com/tech/2013/04/11/bitcoin-electronic-cash-beloved-by-hackers/ |title=Bitcoin, the nationless electronic cash beloved by hackers, bursts into financial mainstream |archiveurl=http://archive.is/YwB03 |archivedate=2013-04-29 |deadurl=no}}. Fox News (11 April 2013). Retrieved on 20 April 2013.</ref><ref>{{cite web |url=http://blog.aarp.org/2013/04/11/bitcoin-currency-hackers-make-money-investing-in-bitcoins-scams/ |title=Bitcoin Currency, Hackers Make Money, Investing in Bitcoins, Scams&nbsp;– AARP |archiveurl=http://archive.is/98mWj |archivedate=2013-04-29 |deadurl=no}}. Blog.aarp.org (19 March 2013). Retrieved on 20 April 2013.</ref>

In June 2013, Bitcoin Foundation board member Jon Matonis wrote in ''Forbes'' that he received a warning letter from California's Department of Financial Institutions accusing the foundation of unlicensed money transmission, Matonis denying the foundation is engaged in money transmission and saying he viewed the case as "an opportunity to educate state regulators."<ref name=NBCnews20130624>{{cite web |url=http://www.nbcnews.com/technology/bitcoin-losing-shine-after-hitting-spotlight-6C10066339 |title=Bitcoin losing shine after hitting the spotlight |last=Coldewey |first=Devin |date=June 24, 2013 |publisher=NBC News |archiveurl=http://www.webcitation.org/6IQjnlc52 |archivedate=July 27, 2013 }}</ref>

In late July 2013, the industry group Committee for the Establishment of the Digital Asset Transfer Authority began to form to set best practices and standards, to work with regulators and policymakers to adapt existing currency requirements to digital currency technology and business models and develop risk management standards.<ref name=WashPost20130730>{{cite web |url=http://www.washingtonpost.com/business/technology/bitcoin-industry-leaders-set-up-standards-group/2013/07/30/8ce4d73c-f94c-11e2-afc1-c850c6ee5af8_story.html |title=Bitcoin, others set up standards group |last=Tsukayama |first= Hayley |date=July 30, 2013 |website=The Washington Post |archiveurl=http://www.webcitation.org/6IXzf8vD2 |archivedate=August 1, 2013 }}</ref>

The Cryptocurrency Legal Advocacy Group (CLAG) stressed the importance for taxpayers to determine whether taxes are due on a bitcoin-related transaction based on whether one has experienced a "realization event": when a taxpayer has provided a service in exchange for bitcoins, a realization event has probably occurred and any gain or loss would likely be calculated using fair market values for the service provided."<ref name="BitCoin Tax issues Oct 2012">{{cite journal | title=2012 TNT 209-4 NEWS ANALYSIS: VIRTUAL CURRENCY: A NEW WORRY FOR TAX ADMINISTRATORS?. (Release Date: OCTOBER 17, 2012) (Doc 2012-21516) | author=Stewart, David D. and Soong Johnston, Stephanie D. | journal=Tax Notes Today | year=2012 | month=29 October | volume=2012 TNT 209-4 | issue=2012 TNT 209–4}}</ref>
The Cryptocurrency Legal Advocacy Group (CLAG) stressed the importance for taxpayers to determine whether taxes are due on a bitcoin-related transaction based on whether one has experienced a "realization event": when a taxpayer has provided a service in exchange for bitcoins, a realization event has probably occurred and any gain or loss would likely be calculated using fair market values for the service provided."<ref name="BitCoin Tax issues Oct 2012">{{cite journal | title=2012 TNT 209-4 NEWS ANALYSIS: VIRTUAL CURRENCY: A NEW WORRY FOR TAX ADMINISTRATORS?. (Release Date: OCTOBER 17, 2012) (Doc 2012-21516) | author=Stewart, David D. and Soong Johnston, Stephanie D. | journal=Tax Notes Today | year=2012 | month=29 October | volume=2012 TNT 209-4 | issue=2012 TNT 209–4}}</ref>


In August 2013 the German Finance Ministry characterized Bitcoin as a [[unit of account]],<ref name=Marketwatch20130819>{{cite web |url=http://blogs.marketwatch.com/thetell/2013/08/19/bitcoins-are-private-money-in-germany/ |title=Bitcoins are private money in Germany |last=Vaishampayan |first=Saumya |date=August 19, 2013 |website=[[Marketwatch]] |archiveurl=http://www.webcitation.org/6JJIqfMJn |archivedate=September 1, 2013 }}</ref><ref name=FAZ20130816/> usable in [[Clearing house (finance)|multilateral clearing circle]]s and subject to capital gains tax if held less than one year.<ref name=FAZ20130816>{{cite news |url=http://www.faz.net/aktuell/finanzen/devisen-rohstoffe/digitale-waehrung-deutschland-erkennt-bitcoins-als-privates-geld-an-12535059.html |title=Deutschland erkennt Bitcoins als privates Geld an (Germany recognizes Bitcoin as private money) |last=Nestler |first=Franz |date=August 16, 2013 |website=[[Frankfurter Allgemeine Zeitung]] |archiveurl= |archivedate= }}</ref>
In August 2013 the German Finance Ministry characterized Bitcoin as a [[unit of account]],<ref name=Marketwatch20130819/><ref name=FAZ20130816/> usable in [[Clearing house (finance)|multilateral clearing circle]]s and subject to capital gains tax if held less than one year.<ref name=FAZ20130816>{{cite news |url=http://www.faz.net/aktuell/finanzen/devisen-rohstoffe/digitale-waehrung-deutschland-erkennt-bitcoins-als-privates-geld-an-12535059.html |title=Deutschland erkennt Bitcoins als privates Geld an (Germany recognizes Bitcoin as private money) |last=Nestler |first=Franz |date=August 16, 2013 |website=[[Frankfurter Allgemeine Zeitung]] |archiveurl= |archivedate= }}</ref>


==Criminal use==
==Reception==
Bitcoins have acquired a reputation for use by criminals to purchase drugs, launder money, and gamble. While there is some merit to these claims, as of 2013 Bitcoins do not appear to be extensively used in money laundering. Gambling with Bitcoins is popular and accounts for a large percentage of Bitcoin transactions (although a smaller percentage of transactions by value), and a significant proportion of Bitcoin activity can be linked to the purchase of illegal drugs.


Although bitcoin is promoted as a [[digital currency]], many commentators have criticized bitcoin's volatile [[exchange rate]], relatively inflexible supply, high risk of loss, and minimal use in trade.<ref name="Wired.co.UK"/><ref name=Krugman1 /><ref>{{cite web |url=http://www.washingtonpost.com/blogs/wonkblog/wp/2013/04/11/yes-bitcoin-is-volatile-its-still-got-defenders/ |title=Yes, Bitcoin is volatile. But it's still got defenders |archiveurl=http://archive.is/cnWeq |archivedate=2013-04-29 |deadurl=no}}. Wonkblog (11 April 2013). Retrieved on 20 April 2013.</ref><ref name=Bloomber89>{{cite web|last=Zeitlin|first=Matthew|title=Bitcoin's Wild Ride Shows It's Not Real Money|url=http://www.bloomberg.com/news/2013-04-11/bitcoin-s-wild-ride-shows-its-not-real-money.html|publisher=Bloomberg L.P.|date=11 April 2013 |archiveurl=http://archive.is/qfgrN |archivedate=2013-04-29 |deadurl=no}}</ref>
Named a "shady online currency [that] is starting to gain legitimacy in certain parts of the world" by CNN,<ref name=cnn>{{cite web | url=http://finance.fortune.cnn.com/2012/12/18/bitcoin-money-laundering/ | title=Bitcoin looks primed for money laundering | publisher=CNN | work=money.cnn.com | date=December 18, 2012 | accessdate=18 October 2013 | author=Sanati, Cyrus}}</ref> ''[[The Washington Post]]'' has labelled it "the currency of choice for seedy online activities."<ref name=washp>{{cite web | url=http://articles.washingtonpost.com/2013-10-02/business/42613812_1_digital-currency-federal-authorities-reputation | title=Authorities shut down Silk Road, the world’s largest Bitcoin-based drug market | work=The Washington Post | date=October 2, 2013 | accessdate=21 October 2013 | author=Timothy B. Lee and Hayley Tsukayama}}</ref> The FBI stated in a 2012 report that "Bitcoins will likely continue to attract cybercriminals who view it as a means to move or steal funds".<ref name="fbi_report"/> Steven Strauss, a Harvard public policy professor, suggested in 2013 that "if Bitcoins facilitate too much drug-dealing or money laundering, the U.S. government could make their possession illegal."<ref>{{cite web | url=http://www.huffingtonpost.com/steven-strauss/bitcoin_b_3081812.html | title=Nine Trust-Based Problems With Bitcoin | publisher=TheHuffingtonPost.com, Inc | work=huffingtonpost.com | date=04/14/201 | accessdate=20 October 2013 | author=Strauss, Steven}}</ref> A 2013 [[U.S. Securities and Exchange Commission|SEC]] filing made by a Bitcoin investment vehicle also mentioned the possibility that Bitcoins would become illegal.<ref name=toomanyspecs/>


CNN has called Bitcoins a "shady online currency,"<ref name="cnn"/> and its links to criminal activities such as money laundering have prompted scrutiny from the FBI, US Senate, and the State of New York.
In 2013 ''[[The Guardian]]'' reported that the currency was primarily used to purchase illegal drugs and for online gambling,<ref name=mainly>{{cite web | url=http://www.theguardian.com/world/2013/mar/22/silk-road-online-drug-marketplace | title=Silk Road: the online drug marketplace that officials seem powerless to stop | publisher=Guardian News and Media Limited | work=theguardian.com | date=22 March 2013 | accessdate=20 October 2013 | author=Ball, James}}</ref> and ''[[The Huffington Post]]'' stated that "online gambling accounts for a huge portion of Bitcoin activity."<ref>{{cite web | url=http://www.huffingtonpost.co.uk/tommy-wyher/bitcoin_b_4125434.html | title=The Rise and Rise of Bitcoin | publisher=Thehuffingtonpost.com, Inc. | work=The Huffington Post | date=2013-10-19 | accessdate=21 October 2013 | author=Wyher, Tommy}}</ref> Legitimate transactions are thought to be far less than the number involved in the purchase of drugs,<ref>{{cite web | url=http://www.forbes.com/sites/quora/2013/10/02/how-will-the-fbi-shut-down-of-silk-road-affect-bitcoins/ | title=How Will The FBI Shut Down Of Silk Road Affect Bitcoins? | publisher=Forbes | work=Quora | date=10/02/201 | accessdate=21 October 2013 | author=John Jeffrey Mardlin}}</ref> and roughly one half of all transactions made using Bitcoins are bets placed at a single online gaming website.<ref>{{cite web | url=http://arstechnica.com/business/2013/08/firm-says-online-gambling-accounts-for-almost-half-of-all-bitcoin-transactions/ | title=Firm says online gambling accounts for almost half of all Bitcoin transactions | publisher=Conte Naste | work=Ars Technica | date=Aug 24 2013 | accessdate=21 October 2013 | author=Geuss, Megan}}</ref> In 2012, an academic from the Carnegie Mellon CyLab and the Information Networking Institute estimated that 4.5 to 9% of all Bitcoins spent were for purchases of drugs at a single online market, Silk Road.<ref name=cmacademic>{{cite conference | url=http://www.andrew.cmu.edu/user/nicolasc/publications/Christin-WWW13.pdf | title=Traveling the Silk Road: A Measurement Analysis of a Large Anonymous Online Marketplace | publisher=Carnegie Mellon INI/CyLab | accessdate=22 October 2013 | author=Christin, Nicolas | year=2013 | pages=8}}</ref> However, as the majority of the Bitcoin transactions were at this time speculative in nature, this academic asserts that drugs constituted a much larger percentage of the products and services bought using Bitcoins.<ref name=cmacademic/>

Several news outlets assert that the popularity of Bitcoins hinges on the ability to use them to purchase illegal substances.<ref name=econ/> In addition to such utility, Bitcoins are thought by the FBI as a potential tool of money launderers,<ref name=fbi_report/> and ''The Huffington Post'' stated in 2013 that Bitcoins are the "preferred currency of some online gun dealers," which allows the purchase of arms without background checks.<ref>{{cite web | url=http://www.huffingtonpost.com/2013/04/15/bitcoin-guns_n_3070828.html | title=How Bitcoin Sales Of Guns Could Undermine New Rules | publisher=TheHuffingtonPost.com, Inc. | work=huffingtonpost.com | date=2013-04-15 | accessdate=20 October 2013 | author=Smith, Gerry}}</ref> Such links to illicit activity have attracted the attention of financial regulators, legislative bodies, and law enforcement.<ref>{{cite web | url=http://www.bloomberg.com/news/2013-08-08/did-the-sec-just-validate-bitcoin-no-.html | title=The SEC Shows Why Bitcoin Is Doomed | publisher=Bloomberg LP | work=bloomberg.com | date=Aug 8, 2013 | accessdate=20 October 2013 | author=Lavin, Tim}}</ref>

Although there are fears that Bitcoins may be used to launder money, the FBI stated in 2012 that, while the potential for money laundering exists, there were no known instances of this occurring.<ref name=fbi_report>{{cite web | url=http://cryptome.org/2012/05/fbi-bitcoin.pdf | title=Bitcoins Virtual Currency: Unique Features Present Challenges for Deterring Illicit Activity | publisher=FBI | work=Cyber Intelligence Section and Criminal Intelligence Section | date=24 April 2012 | accessdate=20 October 2013}}</ref> However, in 2013 US authorities seized assets belonging to Mt. Gox, a service that allowed users to exchange Bitcoins for US dollars.<ref>{{cite web | url=http://gawker.com/feds-seize-assets-of-worlds-largest-bitcoin-exchange-506790294 | title=Feds Seize Assets of World's Largest Bitcoin Exchange | publisher=Gawker Media | work=gawker.com | date=2013-05-15 | accessdate=20 October 2013 | author=Chen, Adrian}}</ref> Some say one obstacle to Bitcoins becoming widely used to launder money may be the fact that transaction history is public although the individuals themselves are thought to remain anonymous.<ref name=FistfulPaper201308>{{cite web |url=http://cseweb.ucsd.edu/~smeiklejohn/files/imc13.pdf |title=A Fistful of Bitcoins: Characterizing Payments Among Men with No Names |last=Meiklejohn |first=Sarah ''et al.'' |date=October 23, 2013 (formal publication) |publisher=Association for Computing Machinery (ACM) |archiveurl= |archivedate=September __, 2013 }} • Paper is explained by {{cite web |url=http://www.pcworld.com/article/2047608/bitcoin-offers-privacy-as-long-as-you-dont-cash-out-or-spend-it.html |title=Bitcoin offers privacy—as long as you don't cash out or spend it |last=Kirk |first=Jeremy |date=August 28, 2013 |website=PC World |archiveurl= |archivedate=September __, 2013 }}</ref>

===Botnet mining===
In June 2011, [[Symantec]] warned about the possibility of [[botnet]]s engaging in covert mining of bitcoins,<ref>{{cite web|author=Peter Coogan |url=http://www.symantec.com/connect/blogs/bitcoin-botnet-mining |title=Bitcoin Botnet Mining |work=Symantec.com |date=17 June 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/uusZ |archivedate=2012-09-14 |deadurl=no}}</ref><ref>{{cite web|url=http://www.zdnet.com/blog/security/researchers-find-malware-rigged-with-bitcoin-miner/8934 |title=Researchers find malware rigged with Bitcoin miner |publisher=ZDNet |date=29 June 2011 |accessdate = 24 January 2012 |archiveurl=http://archive.is/7Uhft |archivedate=2013-01-05 |deadurl=no}}</ref> consuming computing cycles, using extra electricity and possibly increasing the temperature of the computer. Some malware also used the [[parallel computing|parallel processing]] capabilities of the [[GPU]]s built into many modern-day [[video card]]s.<ref>{{Cite news |url=http://www.theregister.co.uk/2011/08/16/gpu_bitcoin_brute_forcing/ |title=Malware mints virtual currency using victim's GPU |date=16 August 2011|first=Dan |last=Goodin |archiveurl=http://archive.is/oDCb |archivedate=2012-12-23 |deadurl=no}}</ref>


Bitcoin has been reviewed by several financial journalists and economists to mixed acclaim. Its sustainability as a currency is often questioned:
==In the media==
* In 2011, economist [[Paul Krugman]], wrote that "[bitcoin] has fluctuated sharply, but overall it has soared. So buying into [bitcoin] has, at least so far, been a good investment. But does that make the experiment a success? Um, no. What we want from a monetary system isn’t to make people holding money rich; we want it to facilitate transactions and make the economy as a whole rich. And that’s not at all what is happening in [bitcoin]."<ref name=Krugman1>{{cite web|last=Krugman|first=Paul|title=Golden Cyberfetters|url=http://krugman.blogs.nytimes.com/2011/09/07/golden-cyberfetters/|publisher=New York Times|date=7 September 2011 |archiveurl=http://archive.is/jzUoz |archivedate=2013-04-11 |deadurl=no}}</ref> In 2013, Krugman stated that unlike gold or paper currencies, bitcoin derives its value solely from a self-fulfilling expectation that others will accept it as payment.<ref>{{cite news|last=Krugman|first=Paul|title=The Antisocial Network|url=http://www.nytimes.com/2013/04/15/opinion/krugman-the-antisocial-network.html|newspaper=New York Times|date=14 April 2013 |archiveurl=http://archive.is/jdAYc |archivedate=2013-04-29 |deadurl=no}}</ref> He also stated that it is unnecessarily wasteful to consume real resources, such as electric power, on the creation of bitcoins.<ref>{{cite news|last=Krugman|first=Paul|title=Adam Smith Hates Bitcoin|url=http://krugman.blogs.nytimes.com/2013/04/12/adam-smith-hates-bitcoin/|newspaper=New York Times|date=12 April 2013 |archiveurl=http://archive.is/TAgyQ |archivedate=2013-04-29 |deadurl=no}}</ref>
In January 2012, Bitcoin was featured as the main subject within a fictionalized trial on the [[CBS]] legal drama ''[[The Good Wife]]'' in the third season episode "[[The Good Wife (season 3)#Episodes|Bitcoin for Dummies]]”<ref name="The Good Wife">{{cite web|last=Toepfer|first=Susan|title='The Good Wife' Season 3, Episode 13, 'Bitcoin for Dummies': TV Recap|url=http://blogs.wsj.com/speakeasy/2012/01/16/the-good-wife-season-3-episode-13-bitcoin-for-dummies-tv-recap/|publisher=The Wall Street Journal|date=16 January 2012 |archiveurl=http://archive.is/WyMXp |archivedate=2013-04-12 |deadurl=no}}</ref>
* In March 2013, Nick Colas a Chief Market Strategist at ConvergEx Group, a [[Bank of New York Mellon]] investment firm&nbsp;– analyzed bitcoin, saying "there is much to learn from [bitcoin] in the world of stateless currencies," and that "confidence in money as a store of value is the ultimate driver of its value, both in the cyber and real worlds. I have no idea which way [bitcoins] will trade in the next 2 days or 2 years, but the whole process of starting a new Internet currency is a great case study in how real people use real currency."<ref name=BIConvergEx>{{cite web|last=Boesler|first=Matthew|title=ANALYST: The Rise Of Bitcoin Teaches A Tremendous Lesson About Global Economics|url=http://www.businessinsider.com/global-economics-lesson-from-bitcoin-2013-3|publisher=Business Insider|date=7 March 2013 |archiveurl=http://archive.is/YqHXP |archivedate=2013-04-10 |deadurl=no}}</ref>
* In April 2013, an analysis by financial journalist [[Felix Salmon]]—formerly of ''[[Conde Nast Portfolio|Portfolio Magazine]] ''and ''[[Euromoney]],'' and a blogging editor for [[Reuters]]—considered the current price of bitcoins to be a [[Economic bubble|bubble]]. He noted that while the value of bitcoins is strongly affected by [[news media]] exposure and that they are an "uncomfortable combination of commodity and currency," Bitcoin was "in many ways the best and cleanest payments mechanism the world has ever seen."<ref>{{cite web |url=https://medium.com/money-banking/2b5ef79482cb |title=The Bitcoin Bubble and the Future of Currency, Felix Salmon, Financial blogger at Reuters 3 April 2013 |archiveurl=http://archive.is/K6uFF |archivedate=2013-04-29 |deadurl=no}}. Medium.com (3 April 2013). Retrieved on 20 April 2013.</ref>
* Economist [[John Quiggin]] has claimed that "Bitcoin is perhaps the finest example of a pure bubble", and that it provides a conclusive refutation of the [[efficient-market hypothesis]] (EMH).<ref name="QuigginNI">{{cite news|url=http://nationalinterest.org/commentary/the-bitcoin-bubble-bad-hypothesis-8353|title=The Bitcoin Bubble and a Bad Hypothesis|last=Quiggin|first=John|work=The National Interest|date=16 April 2013 |archiveurl=http://archive.is/IQVny |archivedate=2013-04-29 |deadurl=no}}</ref> While other assets used as currency—such as gold, tobacco and U.S. dollars—have value independent of people's willingness to accept them as payment, Quiggin argues that "in the case of Bitcoin there is no source of value whatsoever" and that:
<blockquote>
Since Bitcoins do not generate any actual earnings, they must appreciate in value to ensure that people are willing to hold them. But an endless appreciation, with no flow of earnings or liquidation value, is precisely the kind of bubble the EMH says can’t happen.
</blockquote>
* Carnegie Mellon Professor Nicholas Christin studied online black market [[Silk Road (marketplace)|Silk Road]] and concluded that law enforcement authorities could stop it by disrupting its use of bitcoin for anonymous transactions.<ref name="Guardian Ball">{{cite web|last=Ball|first=James|title=Silk Road: the online drug marketplace that officials seem powerless to stop|url=http://www.guardian.co.uk/world/2013/mar/22/silk-road-online-drug-marketplace|publisher=The Guardian|date=22 March 2013 |archiveurl=http://archive.is/wNXAj |archivedate=2013-04-29 |deadurl=no}}</ref> As of September 2012, Christin estimated that on Silk Road, where all transactions are required to use bitcoin, volume amounted to approximately $1.9 million per month.<ref name="Economist Anonymous">{{cite news|title=Monetarists Anonymous|url=http://www.economist.com/node/21563752|date=29 Sep 2012|newspaper=The Economist |archiveurl=http://archive.is/j6sDZ |archivedate=2013-01-02 |deadurl=no}}</ref> Online arms merchant [[Executive Outcomes]], which dealt in illicit goods, accepted only bitcoin in payment, allegedly to ensure anonymity. Christin stated that bitcoin increased the level of anonymity in such transactions, possibly making it more difficult to identify the buyer of a weapon used to commit a crime.<ref name="Huffington Gun Trade">{{cite web|last=Smith|first=Gerry|title=How Bitcoin Sales Of Guns Could Undermine New Rules|url=http://www.huffingtonpost.com/2013/04/15/bitcoin-guns_n_3070828.html|publisher=Huffington Post|date=15 April 2013 |archiveurl=http://archive.is/kgfYT |archivedate=2013-04-29 |deadurl=no}}</ref>


==See also==
==See also==

Revision as of 16:23, 28 October 2013

Bitcoin
A digital Bitcoin wallet
Unit
SymbolBTC, XBT,[1] , ฿ (note: this also is the baht symbol),[2] Ƀ[3]
Denominations
Subunit
 .001mBTC (millicoin)
 .000001μBTC (microcoin)
 .00000001satoshi[4]
Demographics
Date of introduction3 January 2009Bitcoin Genesis Block
User(s)International
Issuance
LedgerThe majority of the Bitcoin peer-to-peer network regulates transactions and balances.[5][6]
Valuation
IssuanceLimited release
 SourceTotal BTC in Circulation
 MethodThe rate of new bitcoin creation will be halved every four years until there are 21 million BTC[7]
A common Bitcoin logo.

Bitcoin (sign: ; code: BTC or XBT[8]) is a distributed peer-to-peer digital currency that functions without the intermediation of any central authority.[9] The concept was introduced in a 2008 paper by a pseudonymous developer known only as "Satoshi Nakamoto".[5] Is the currency generated by the malware Silent Miner, since it is completely anonymous and does not traceable.

Bitcoin is called a cryptocurrency since it is decentralized and uses cryptography to prevent double-spending, a significant challenge inherent to digital currencies.[9] Once validated, every individual transaction is permanently recorded in a public ledger known as the blockchain.[9] The calculations required to authenticate Bitcoin transactions are completed using a network of private computers often specially tailored to this task.[10] As of May 2013, the Bitcoin network processing power "exceeds the combined processing strength of the top 500 most powerful supercomputers".[11] The operators of these computers, known as "miners", are rewarded with transaction fees and newly minted bitcoins. However, new bitcoins are created at an ever-decreasing rate.[9] Once 21 million bitcoins are distributed, issuance will cease.[9] As of August 2013, approximately 11.5 million bitcoins were in circulation.[12]

In 2012, The Economist reasoned that Bitcoin has been popular due to "its role in dodgy online markets,"[13] and in 2013 the FBI shut down one such service, Silk Road, which allowed the sale of illegal drugs for bitcoins. However, bitcoins are increasingly used as payment for legitimate products and services.[14] Notable vendors include Wordpress, OkCupid, Reddit, and Chinese Internet giant Baidu.[15]

Speculators have been attracted to Bitcoin, fueling volatility and price swings. In July 2013, Cameron and Tyler Winklevoss asserted that "there is relatively small use of bitcoins in the retail and commercial marketplace in comparison to relatively large use by speculators."[16]

Transactions

Bitcoin wallets and addresses

A bitcoin transaction log showing addresses.

Bitcoin addresses are randomly-generated cryptographic public key pairs.[5] Each public address consists of around 33 numbers and letters, beginning with the digit 1 or 3, as in the example of 175tWpb8K1S7NmH4Zx6rewF9WQrcZv245W.[17]

The ability to transact bitcoins without the assistance of a central registry is guaranteed in part by the availability of a virtually unlimited supply of unique addresses which can be generated and disposed of at will. A bitcoin address has three fundamental components:

  1. A bitcoin balance - which is a matter of public record. This balance can be ascertained by looking up the transactions to and from any public address in the world-wide register of all bitcoin transactions, called the "blockchain".
  2. A public address - which may be shared with anyone and is used to specify a recipient when sending bitcoins.
  3. A private key - which is kept secret by the person or entity that owns the address. All valid transfers of bitcoins are digitally signed using the private key associated with the address sending the bitcoins.

A bitcoin user may manage one or more bitcoin addresses by using a digital wallet. Wallets let users send bitcoins, request payment, calculate the total balance of addresses in use, and generate new addresses as needed. Wallets are responsible for keeping the private keys secret, for example by encrypting the wallet data with a password or by requiring two-factor authenticated logins.

Bitcoin wallets have been implemented as stand-alone software applications, web applications, hardware devices, and paper wallets.

Stand-alone software wallets

Bitcoin client software is available for Linux, Windows, Mac OS X, IOS, and Android. These applications directly participate in the peer-to-peer bitcoin network and store the blockchain (or a portion of the blockchain) as it grows. In the case of mobile apps for IOS and Android, QR codes are used to simplify transactions between buyers and sellers.[18]

The first Bitcoin clients, created by the developer of Bitcoin, are bitcoind and Bitcoin-qt (bitcoind's GUI counterpart), available for Linux, Windows, and Mac OS X.

Web applications with integrated wallets

Many bitcoin websites provide addresses associated with an online account to hold bitcoin funds on the user's behalf. Some of these sites work like bank accounts for bitcoin, even paying interest. Other sites function primarily as exchanges, facilitating the sale and purchase of bitcoin with other currencies such as US Dollars or Euros.

Hardware wallets

Theoretically, the services typically associated with a bitcoin wallet could be built into a stand-alone hardware device, and several projects aim to bring such a device to market.[19]

File:Sample Bitcoin Paper Wallet.png
Example of a bitcoin paper wallet with private key hidden beneath tamper-evident seals.

Paper wallets and "physical" bitcoins

Any valid bitcoin address keys may be printed on paper and used to store bitcoins offline. Compared with "hot wallets" (wallets that are connected to the Internet) these non-digital offline paper wallets are considered a "cold storage" mechanism better suited for safekeeping bitcoins.[20] Douglas Feigelson of BitBills filed a patent application “Creating And Using Digital Currency” with the United States Patent and Trademark Office on December 23, 2011.[21]

Various vendors offer banknotes, coins and cards denominated in bitcoins. Unlike government issued currency or precious bullion, the bitcoin value of these instruments is not integral to the banknote or coin itself. Instead, the bitcoin balance is bound to the private key printed on the banknote or embedded within the coin. Some of these instruments employ a tamper-evident seal meant to hide the private key so that the bitcoin balance cannot be transferred without breaking the seal.

Payment network and mining

A diagram of a bitcoin transfer.

The Bitcoin network protocol operates to provide solutions to the problems associated with creating a decentralized currency and a peer-to-peer payment network. Key among them is the use of a blockchain to achieve consensus and to solve the double-spending problem.

A bitcoin is defined by a chain of digitally-signed transactions that began with its creation as a block reward through bitcoin mining. Each owner transfers bitcoins to the next by digitally signing them over to the next owner in a Bitcoin transaction. A payee can then verify each previous transaction to verify the chain of ownership.

The network timestamps transactions by including them in blocks that form an ongoing chain called the blockchain. Such blocks cannot be changed without redoing the work that was required to create each block since the modified block. The longest chain serves not only as proof of the sequence of events but also records that this sequence of events was verified by a majority of the Bitcoin network's computing power. As long as a majority of computing power is controlled by nodes that are not cooperating to attack the network, they will generate the longest chain of records and outpace attackers.

The network itself requires minimal structure to share transactions. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will. Upon reconnection, a node will download and verify new blocks from other nodes to complete its local copy of the blockchain.[5][6]

History

Bitcoin is the first cryptocurrency, a form of money that uses cryptography to control its creation and management, rather than relying on central authorities.[9] However, not all of the technologies and concepts that make up Bitcoin are new; Satoshi Nakamoto integrated many existing ideas from the cypherpunk community when creating Bitcoin.[22]

Timeline

  • 2008–2009
    • In 2008, Satoshi Nakamoto posted a paper describing the Bitcoin protocol on the internet.[5][23][24][25]
    • In 2009, the Bitcoin network came into existence with the release of the first open source Bitcoin client and the issuance of the first bitcoins.[23][26][27][28]
    • 2009-01-03 - "Satoshi Nakamoto" mines the first block of bitcoins ever (known as the "genesis block"), which had a reward of 50 bitcoins.
  • 2010
    • The prices for the first bitcoin transactions were negotiated by individuals on the bitcointalk forums. One notable transaction involved a 10,000 BTC pizza.[23]
    • On 6 August, a major vulnerability in the Bitcoin protocol was spotted. Transactions weren't properly verified before they were included in the transaction log or "block chain" which allowed for users to bypass Bitcoin's economic restrictions and create an indefinite number of bitcoins.[29][30]
    • On 15 August, the major vulnerability was exploited. Over 184 billion bitcoins were generated in a transaction, and sent to two addresses on the network. Within hours, the transaction was spotted[31][32] and erased from the transaction log after the bug was fixed and the network forked to an updated version of the Bitcoin protocol. This was the only major security flaw found and exploited in Bitcoin's history.[29][30]
  • 2011–2012
    • In June 2011, Wikileaks[33] and other organizations began to accept bitcoins for donations. The Electronic Frontier Foundation temporarily suspended bitcoin acceptance, citing concerns about a lack of legal precedent about new currency systems, and that they "generally don't endorse any type of product or service."[34] The EFF's decision was changed in 17 May 2013.[35]
    • In late 2011, the exchange rate of bitcoin crashed from over $30 in June to below $2 in October.
    • In January 2012, Bitcoin was featured as the main subject within a fictionalized trial on the CBS legal drama The Good Wife in the third season episode "Bitcoin for Dummies". The host of CNBC's Mad Money, Jim Cramer, played himself in a courtroom scene where he testifies that he doesn’t consider bitcoin a true currency, saying “There’s no central bank to regulate it; it’s digital and functions completely peer to peer.”[36]
    • In October 2012, BitPay reported having over 1,000 merchants accepting Bitcoin under its payment processing service.[37]
  • 2013
    • February
      • The Bitcoin-based payment processor Coinbase reported selling $1 million in bitcoins in a single month at over $22 per bitcoin.[38]
      • The Internet Archive announced that it is ready to accept donations as bitcoins and that it intends to give employees the option to receive portions of their salaries in Bitcoin currency.[39]
    • March
      • The Bitcoin transaction log or "block chain" temporarily forked into two independent logs with differing rules on how transactions could be accepted. The Mt.Gox exchange briefly halted Bitcoin deposits and the exchange rate briefly dipped by 23% to $37 as the event occurred[40][41] before recovering to previous level of approximately $48 in the following hours.[42]
      • In the US, the Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as Bitcoin, classifying American "Bitcoin miners" who sell their generated bitcoins as Money Service Businesses (or MSBs), that may be subject to registration and other legal obligations.[43][44][45]
    • April
      • Payment processor BitInstant and Mt.Gox experienced processing delays due to insufficient capacity.[46]
      • On 10 April, the bitcoin exchange rate dropped from $266 to $76 before returning to $160 within six hours.[47]
      • Bitcoin gained greater recognition when services such as OkCupid and Foodler began accepting it for payment.[48]
    • May
      • On 15 May 2013, the US authorities seized accounts associated with Mt. Gox after discovering that it had not registered as a money transmitter with FinCEN in the US.[49][50]
      • The US-based bitcoin company Coinbase announces a $5 million Series A investment, the largest funding round for a bitcoin company.[51]
    • June
    • July
      • A project under way in Kenya is linking Bitcoin with M-Pesa, a popular mobile payments system, in an experiment designed to spur innovative payments in Africa.[55]
      • July 30, 2013—The Foreign Exchange Administration and Policy Department in Thailand stated that Bitcoin lacks any legal framework and would therefore be illegal, which effectively banned trading on Bitcoin exchanges in the country.[56][57] According to Vitalik Buterin, a writer for Bitcoin Magazine, "Bitcoin’s fate in Thailand may give the electronic currency more credibility in some circles." But he was concerned it didn’t bode well for Bitcoin in China.[58]
      • As of July 2013, BitPay handled bitcoin transactions for more than 4,500 companies.[58]
    • August
      • Federal Judge Amos Mazzant of the Eastern District of Texas of the Fifth Circuit ruled that bitcoins are "a currency or a form of money" (specifically securities as defined by Federal Securities Laws), and as such were subject to the court's jurisdiction.[59] The case, brought by the U.S. Securities and Exchange Commission, is ongoing.[60]
      • Germany's Finance Ministry subsumed Bitcoins under the term "unit of account"—a financial instrument—though not as e-money or a functional currency, a classification nonetheless having legal and tax implications.[61]
    • October

Satoshi Nakamoto

Satoshi Nakamoto is a pseudonym for the unknown person or people who designed the original Bitcoin protocol in 2008 and launched the network in 2009. Nakamoto was responsible for creating the majority of the Bitcoin software and was active in making modifications and posting technical information on the BitcoinTalk Forum.[67]

Investigations into the real identity of Satoshi Nakamoto have been attempted by The New Yorker and Fast Company. Fast Company's investigation brought up circumstantial evidence linking an encryption patent application filed by Neal King, Vladimir Oksman and Charles Bry on 15 August 2008, and the bitcoin.org domain name which was registered 72 hours later. The patent application (#20100042841) contained networking and encryption technologies similar to Bitcoin's, and textual analysis revealed that the phrase "...computationally impractical to reverse" appeared in both the patent application and bitcoin's whitepaper.[5] All three inventors explicitly denied being Satoshi Nakamoto.[68][69] In May 2013, Ted Nelson speculated that Japanese mathematician Shinichi Mochizuki is Satoshi Nakamoto.[70]

Nakamoto's involvement with Bitcoin does not appear to extend past mid-2010.[71] In April 2011, Nakamoto communicated with a Bitcoin contributor saying he had "moved on to other things".[72]

The fork of March 2013

On 12 March 2013, a Bitcoin miner running version 0.8.0 of the Bitcoin software created a large block that was incompatible with earlier versions of the Bitcoin software due to its size. This created a split or "fork" in the block chain since older versions of the software did not accept this block as valid. Computers with the recent version of the software accepted the block and continued to build on the diverging chain, whereas older versions of the software rejected it and continued extending the block chain without the offending block. This split resulted in two separate transaction logs being formed without clear consensus, which allowed for the same funds to be spent differently on each chain. In response, the Mt.Gox exchange temporarily halted Bitcoin deposits.[73] The exchange rate fell 23% to $37 on the Mt.Gox exchange but rose most of the way back to its prior level of $48.[40][41]

Developers at bitcoin.org resolved the split by recommending that users downgrade to "version 0.7", which utilized the oldest transaction log in the split. User funds largely remained unaffected and were available when network consensus was reached.[74] The network reached consensus and continued to operate as normal a few hours after the split.[75]

Regulatory issues

On 18 March 2013, the Financial Crimes Enforcement Network (or FinCEN), a bureau of the United States Department of the Treasury, issued a report regarding centralized and decentralized "virtual currencies" and their legal status within "money services business" (MSB) and Bank Secrecy Act regulations.[45][50] It classified digital currencies and other digital payment systems such as Bitcoin as "virtual currencies" because they are not legal tender under any sovereign jurisdiction. FinCEN cleared American users of Bitcoin of legal obligations[50] by saying, "A user of virtual currency is not an MSB under FinCEN’s regulations and therefore is not subject to MSB registration, reporting, and recordkeeping regulations." However, it held that American entities who generate "virtual currency" such as bitcoins are money transmitters or MSBs if they sell their generated currency for national currency: "...a person that creates units of convertible virtual currency and sells those units to another person for real currency or its equivalent is engaged in transmission to another location and is a money transmitter." This specifically extends to "miners" of the Bitcoin currency who may have to register as MSBs and abide by the legal requirements of being a money transmitter if they sell their generated bitcoins for national currency and are within the United States.[43]

Additionally, FinCEN claimed regulation over American entities that manage bitcoins in a payment processor setting or as an exchanger: "In addition, a person is an exchanger and a money transmitter if the person accepts such de-centralized convertible virtual currency from one person and transmits it to another person as part of the acceptance and transfer of currency, funds, or other value that substitutes for currency."[44][45]

In summary, FinCEN's decision would require Bitcoin exchanges where bitcoins are traded for traditional currencies to disclose large transactions and suspicious activity, comply with money laundering regulations, and collect information about their customers as traditional financial institutions are required to do.[50][76][77]

Patrick Murck of the Bitcoin Foundation criticized FinCEN's report as an "overreach" and claimed that FinCEN "cannot rely on this guidance in any enforcement action".[78][non-primary source needed]

Jennifer Shasky Calvery, the director of FinCEN said, “Virtual currencies are subject to the same rules as other currencies. … Basic money-services business rules apply here.”[50]

In its October 2012 study, Virtual currency schemes, the European Central Bank concluded that the growth of virtual currencies will continue, and, given the currencies' inherent price instability, lack of close regulation, and risk of illegal uses by anonymous users, the Bank warned that periodic examination of developments would be necessary to reassess risks.[79]

In 2013, the U.S. Treasury extended its anti-money laundering regulations to processors of bitcoin transactions.[80][81]

In June 2013, Bitcoin Foundation board member Jon Matonis wrote in Forbes that he received a warning letter from California's Department of Financial Institutions accusing the foundation of unlicensed money transmission, Matonis denying the foundation is engaged in money transmission and saying he viewed the case as "an opportunity to educate state regulators."[82]

In late July 2013, the industry group Committee for the Establishment of the Digital Asset Transfer Authority began to form to set best practices and standards, to work with regulators and policymakers to adapt existing currency requirements to digital currency technology and business models and develop risk management standards.[83]

2013 bitcoin prices

The bitcoin to USD exchange rates at one of the exchanges

The price of a bitcoin reached an all-time high of US$230 on 9 April 2013, up from just $13 at the start of the year.[84] Among the factors which may have contributed to this rise were the European sovereign-debt crisis—particularly the 2012–2013 Cypriot financial crisis—statements by FinCEN improving the currency's legal standing and rising media and Internet interest.[85][86][87][88]

As the market valuation of the total stock of Bitcoins approached 1 billion USD, some commentators called Bitcoin prices a bubble.[89][90][91] In early April 2013, the price per bitcoin dropped from $266 to around $50 and then rose to around $100. Over two weeks starting late June 2013 the price dropped steadily to $70. The price began to recover, peaking once again on October 1 at $140. On October 2nd, The Silk Road was seized by the FBI. This seizure caused the price to collapse to $110 before closing at $123.[92]

Economics

Large fluctuations in the value of Bitcoin have led to criticism of its usefulness as a currency.[93] In addition, its deflationary bias encourages hoarding.[94] This reduces the use value of a currency and has been the downfall of other private currencies.[95] However, currently Bitcoin does see some use as a currency[96] as well as being horded by individuals.[97]

Exchanges

Through various exchanges, bitcoins are bought and sold at a variable price against the value of other currency. Bitcoin has appreciated rapidly in relation to other currencies including the US dollar, euro and British pound.[84][98][99]

Bitcoin exchanges regularly fail, and the vast majority of transactions are completed on a single exchange that was originally a site for trading Magic: The Gathering cards online, Mt. Gox.

According to Reuters, undisclosed documents indicate that banks such as Morgan Stanley and Goldman Sachs have visited Bitcoin exchanges as often as 30 times a day. Employees of international banks and major financial organizations have shown interest in Bitcoin markets as well.[100]

Bitcoin as an investment

Although the Bitcoin Project describes bitcoin exclusively as an "experimental digital currency," [101] bitcoins are often traded as an investment.[102] Critics have accused bitcoin of being a form of investment fraud known as a Ponzi scheme.[103][104] A case study report[105] by the European Central Bank observes that the bitcoin currency system shares some characteristics with Ponzi schemes, but also has characteristics which are distinct from the common aspects of Ponzi schemes as defined by the U.S. Securities and Exchange Commission.

Bitcoins have been described as lacking intrinsic value as an investment because their value depends only on the willingness of users to accept it.[106][107][108] In addition, a study indicated that 45 percent of Bitcoin exchanges end up closing with many customers losing their money.[109]

Like many assets, bitcoins are also subject to theft.

Derivatives on bitcoins are thinly available. One organization offers futures contracts on bitcoins against multiple currencies.[110]

Several bitcoin investors have become entrepreneurs in the evolving bitcoin universe. Efforts are underway to build financial services, new exchanges, and new payment products using bitcoin. Interest in the bitcoin sector has arisen from investment funds, with recent Peter Thiel's Founders Fund investing US$3 million in the sector and the Winklevoss twins making a US$1.5 million investment.[111]

Bitcoin bubble

Many have mentioned speculative bubbles in connection with Bitcoin, and Reuters journalist Felix Salmon correctly predicted the bursting of one such Bitcoin bubble in April 2013.[112]

Alternative to fiat currency

Some have suggested that hording Bitcoins will become a popular activity for individuals living in countries with problem plagued local currencies and that it can be used to circumvent capital controls and international sanctions.

Bitcoins are used to some extent by Argentinians an as an alternative to the official currency,[113] which is stymied by inflation and strict capital controls.[114]

Some Iranians use Bitcoins to evade currency sanctions.[115]

Financial journalists and analysts have speculated that there was a correlation between higher bitcoin usage in Spain and the 2012–2013 Cypriot financial crisis that bitcoin is serving as a sort of financial haven for some European savers.[116]

Implications

Privacy

Bitcoin transactions are seen as relatively anonymous.[117] Bitcoins were the medium of exchange used in the online black market website Silk Road.[118][119] Some Bitcoin proponents are concerned that such associations may bring about negative perceptions of the currency.[120]

The privacy of Bitcoin is the subject of active academic research.[121] Because Bitcoin transactions are broadcast to the entire network, they are inherently public. Using external information, it is possible, though usually difficult, to associate Bitcoin identities with real-life identities[122][123] through analysis of past Bitcoin transactions to reveal patterns that can unmask user identities.[114] Unlike regular banking,[124] which can preserve customer privacy by keeping transaction records private, loose transactional privacy is accomplished in Bitcoin by using many unique addresses for every wallet even though all transactions are published. However, according to the Mercatus Center's Primer for Policymakers (2013), after Bitcoin intermediaries comply with the same bank secrecy regulations required of traditional financial intermediaries, anonymity will be less protected because Bitcoin intermediaries will be required to collect personal customer data.[114]

An IEEE paper proposes a cryptographic extension to Bitcoin called Zerocoin, which would make Bitcoin anonymous and untraceable.[125][126][127][128][129]

Criminal activities

Bitcoins have acquired a reputation for use by criminals to purchase drugs, launder money, and gamble. While there is some merit to these claims, as of 2013 Bitcoins do not appear to be extensively used in money laundering. Gambling with Bitcoins is popular and accounts for a large percentage of Bitcoin transactions (although a smaller percentage of transactions by value), and a significant proportion of Bitcoin activity can be linked to the purchase of illegal drugs.

Named a "shady online currency [that] is starting to gain legitimacy in certain parts of the world" by CNN,[130] The Washington Post has labelled it "the currency of choice for seedy online activities."[131] The FBI stated in a 2012 report that "Bitcoins will likely continue to attract cybercriminals who view it as a means to move or steal funds".[132] Steven Strauss, a Harvard public policy professor, suggested in 2013 that "if Bitcoins facilitate too much drug-dealing or money laundering, the U.S. government could make their possession illegal."[133] A 2013 SEC filing made by a Bitcoin investment vehicle also mentioned the possibility that Bitcoins would become illegal.[16]

In 2013 The Guardian reported that the currency was primarily used to purchase illegal drugs and for online gambling,[134] and The Huffington Post stated that "online gambling accounts for a huge portion of Bitcoin activity."[135] Legitimate transactions are thought to be far less than the number involved in the purchase of drugs,[136] and roughly one half of all transactions made using Bitcoins are bets placed at a single online gaming website.[137] In 2012, an academic from the Carnegie Mellon CyLab and the Information Networking Institute estimated that 4.5 to 9% of all Bitcoins spent were for purchases of drugs at a single online market, Silk Road.[138] However, as the majority of the Bitcoin transactions were at this time speculative in nature, this academic asserts that drugs constituted a much larger percentage of the products and services bought using Bitcoins.[138]

Several news outlets assert that the popularity of Bitcoins hinges on the ability to use them to purchase illegal substances.[13] In addition to such utility, Bitcoins are thought by the FBI as a potential tool of money launderers,[132] and The Huffington Post stated in 2013 that Bitcoins are the "preferred currency of some online gun dealers," which allows the purchase of arms without background checks.[139] Such links to illicit activity have attracted the attention of financial regulators, legislative bodies, and law enforcement.[140]

Although there are fears that Bitcoins may be used to launder money, the FBI stated in 2012 that, while the potential for money laundering exists, there were no known instances of this occurring.[132] However, in 2013 US authorities seized assets belonging to Mt. Gox, a service that allowed users to exchange Bitcoins for US dollars.[141] Some say one obstacle to Bitcoins becoming widely used to launder money may be the fact that transaction history is public although the individuals themselves are thought to remain anonymous.[142]

Energy use and environmental impact

An April 2013 estimate showed that the amount of electricity being used every day to mine bitcoins was about 982 megawatt hours, the amount capable of powering about 31,000 American homes.[143] This was estimated to be about USD $147,000 worth of energy. In comparison, profits made from a day's worth of bitcoin mining were given at about $681,000.

Botnet mining

In June 2011, Symantec warned about the possibility of botnets engaging in covert mining of bitcoins,[144][145] consuming computing cycles, using extra electricity and possibly increasing the temperature of the computer. Some malware also used the parallel processing capabilities of the GPUs built into many modern-day video cards.[146]

Later that month, the Australian Broadcasting Corporation caught an employee using the company's servers to generate Bitcoins without permission.[147]

In mid-August 2011, Bitcoin miner botnets were detected again,[148] and less than three months later bitcoin-mining trojans infecting Mac OS X were also discovered.[149]

Theft and technical vulnerabilities

There have been incidents of theft of bitcoin balances:

  • On 19 June 2011, a security breach of the Mt.Gox bitcoin exchange caused the nominal price of a bitcoin to fraudulently drop to one cent on the Mt.Gox exchange, after a hacker allegedly used credentials from a Mt.Gox auditor's compromised computer illegally to transfer a large number of bitcoins to himself. He used the exchange's software to sell them all nominally, creating a massive "ask" order at any price. Within minutes the price corrected to its correct user-traded value.[150][151][152][153][154][155] Accounts with the equivalent of more than 8,750,000 USD were affected.[152]
  • In July 2011, the operator of Bitomat, the third largest bitcoin exchange, announced that he lost access to his wallet.dat file with about 17,000 bitcoins (roughly equivalent to 220,000 USD at that time). He announced that he would sell the service for the missing amount, aiming to use funds from the sale to refund his customers.[156]
  • In August 2011, MyBitcoin, a now defunct bitcoin transaction processor, declared that it was hacked, which resulted in it being shut down, with paying 49% on customer deposits, leaving more than 78,000 bitcoins (roughly equivalent to 800,000 USD at that time) unaccounted for.[157][158]
  • In early August 2012, a lawsuit was filed in San Francisco court against Bitcoinica — a bitcoin trading venue — claiming about 460,000 USD from the company. Bitcoinica was hacked twice in 2012, which led to allegations of neglecting the safety of customers' money and cheating them out of withdrawal requests.[159][160]
  • In late August 2012, an operation titled Bitcoin Savings and Trust was shut down by the owner, allegedly leaving around 5.6 million USD in bitcoin-based debts; this led to allegations of the operation being a Ponzi scheme.[161][162][163][164] In September 2012, it was reported that the U.S. Securities and Exchange Commission had started an investigation on the case.[165]
  • In September 2012, Bitfloor, a bitcoin exchange, also reported being hacked, with 24,000 bitcoins (roughly equivalent to 250,000 USD) stolen. As a result, Bitfloor suspended operations.[166][167] The same month, Bitfloor resumed operations, with its founder saying that he reported the theft to FBI, and that he is planning to repay the victims, though the time frame for such repayment is unclear.[168]
  • On 3 April 2013, Instawallet, a web-based wallet provider, was hacked,[169] resulting in the theft of over 35,000 bitcoins.[170] With a price of 129.90 USD per bitcoin at the time, or nearly 4.6 million USD in total, Instawallet suspended operations.
  • On 11 August 2013, the Bitcoin Foundation announced that a bug in a pseudorandom number generator within the Android operating system had been exploited to steal from users' wallets, the vulnerability affecting wallets generated by any Android app; fixes were provided 13 August 2013.[171]

Taxation

The Cryptocurrency Legal Advocacy Group (CLAG) stressed the importance for taxpayers to determine whether taxes are due on a bitcoin-related transaction based on whether one has experienced a "realization event": when a taxpayer has provided a service in exchange for bitcoins, a realization event has probably occurred and any gain or loss would likely be calculated using fair market values for the service provided."[172]

In August 2013 the German Finance Ministry characterized Bitcoin as a unit of account,[61][173] usable in multilateral clearing circles and subject to capital gains tax if held less than one year.[173]

Reception

Although bitcoin is promoted as a digital currency, many commentators have criticized bitcoin's volatile exchange rate, relatively inflexible supply, high risk of loss, and minimal use in trade.[109][174][175][176]

CNN has called Bitcoins a "shady online currency,"[130] and its links to criminal activities such as money laundering have prompted scrutiny from the FBI, US Senate, and the State of New York.

Bitcoin has been reviewed by several financial journalists and economists to mixed acclaim. Its sustainability as a currency is often questioned:

  • In 2011, economist Paul Krugman, wrote that "[bitcoin] has fluctuated sharply, but overall it has soared. So buying into [bitcoin] has, at least so far, been a good investment. But does that make the experiment a success? Um, no. What we want from a monetary system isn’t to make people holding money rich; we want it to facilitate transactions and make the economy as a whole rich. And that’s not at all what is happening in [bitcoin]."[174] In 2013, Krugman stated that unlike gold or paper currencies, bitcoin derives its value solely from a self-fulfilling expectation that others will accept it as payment.[177] He also stated that it is unnecessarily wasteful to consume real resources, such as electric power, on the creation of bitcoins.[178]
  • In March 2013, Nick Colas a Chief Market Strategist at ConvergEx Group, a Bank of New York Mellon investment firm – analyzed bitcoin, saying "there is much to learn from [bitcoin] in the world of stateless currencies," and that "confidence in money as a store of value is the ultimate driver of its value, both in the cyber and real worlds. I have no idea which way [bitcoins] will trade in the next 2 days or 2 years, but the whole process of starting a new Internet currency is a great case study in how real people use real currency."[179]
  • In April 2013, an analysis by financial journalist Felix Salmon—formerly of Portfolio Magazine and Euromoney, and a blogging editor for Reuters—considered the current price of bitcoins to be a bubble. He noted that while the value of bitcoins is strongly affected by news media exposure and that they are an "uncomfortable combination of commodity and currency," Bitcoin was "in many ways the best and cleanest payments mechanism the world has ever seen."[180]
  • Economist John Quiggin has claimed that "Bitcoin is perhaps the finest example of a pure bubble", and that it provides a conclusive refutation of the efficient-market hypothesis (EMH).[181] While other assets used as currency—such as gold, tobacco and U.S. dollars—have value independent of people's willingness to accept them as payment, Quiggin argues that "in the case of Bitcoin there is no source of value whatsoever" and that:

Since Bitcoins do not generate any actual earnings, they must appreciate in value to ensure that people are willing to hold them. But an endless appreciation, with no flow of earnings or liquidation value, is precisely the kind of bubble the EMH says can’t happen.

  • Carnegie Mellon Professor Nicholas Christin studied online black market Silk Road and concluded that law enforcement authorities could stop it by disrupting its use of bitcoin for anonymous transactions.[182] As of September 2012, Christin estimated that on Silk Road, where all transactions are required to use bitcoin, volume amounted to approximately $1.9 million per month.[183] Online arms merchant Executive Outcomes, which dealt in illicit goods, accepted only bitcoin in payment, allegedly to ensure anonymity. Christin stated that bitcoin increased the level of anonymity in such transactions, possibly making it more difficult to identify the buyer of a weapon used to commit a crime.[184]

See also

References

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