wikademia>Eme: By: http://en.wikipedia.org/w/index.php?title=Cryptocurrency&action=history

2013-05-29T03:42:26Z

By: http://en.wikipedia.org/w/index.php?title=Cryptocurrency&action=history

New page

A '''cryptocurrency''' is a type of [[digital currency]] which relies on [[cryptography]], usually alongside a [[proof-of-work]] scheme, in order to create and manage the currency.<ref name="ars1">[http://arstechnica.com/business/2013/05/wary-of-bitcoin-a-guide-to-some-other-cryptocurrencies/ Wary of Bitcoin? A guide to some other cryptocurrencies], ars technica, 26-05-2013</ref> Most cryptocurrencies are [[peer-to-peer]] and [[decentralized]],<ref>[http://www.coindesk.com/california-dreaming-coindesk-weekly-review/ California dreaming: The CoinDesk Weekly Review], Coindesk, 26-05-2013</ref><ref>[http://theconversation.com/from-your-wallet-to-google-wallet-your-digital-payment-options-14540 From your wallet to Google Wallet: your digital payment options], The Conversation, 26-05-2013</ref> and are based on the first cryptocurrency, [[Bitcoin]]. They are generally designed to have no [[inflation]] (once all the currency has been produced), in order to keep scarcity and hence value.<ref name="forbes2011">[http://www.forbes.com/forbes/2011/0509/technology-psilocybin-bitcoins-gavin-andresen-crypto-currency.html Crypto currency], Forbes, 26-05-2013</ref><ref>[http://www.americanbanker.com/bankthink/how-cryptocurrencies-could-upend-banks-monetary-role-1057597-1.html?zkPrintable=1&nopagination=1 How Cryptocurrencies Could Upend Banks' Monetary Role], American Banker, 26-05-2013</ref> Cryptocurrencies are also designed to ensure that funds can neither be frozen nor seized.<ref name="forbes2011" /><ref>[http://news.cnet.com/8301-31322_3-57581952-256/heres-why-bitcoin-is-the-future-of-money/ Here's why Bitcoin is the future of money], cnet, 26-05-2013</ref> Existing cryptocurrencies are all [[pseudonymous]], though additions such as [[Zerocoin]] have been suggested, which would allow for [[anonymity]].<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://spar.isi.jhu.edu/~mgreen/ZerocoinOakland.pdf Zerocoin: Anonymous Distributed E-Cash from Bitcoin], The [[Johns Hopkins University]] Department of [[Computer Science]], 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>

==History==
The first cryptocurrency was [[Bitcoin]] which was created in 2009 by [[pseudonymous]] [[developer]] [[Satoshi Nakamoto]],<ref>[http://www.pcworld.com/article/2039184/bitcoin-developer-talks-regulation-open-source-and-the-elusive-satoshi-nakamoto.html Bitcoin developer chats about regulation, open source, and the elusive Satoshi Nakamoto], PCWorld, 26-05-2013</ref> and used [[SHA-256]] as its [[proof-of-work]] scheme.<ref>[http://www.thegenesisblock.com/mining-for-dummies/ What is Bitcoin Mining?], The Genesis Block, 26-05-2013</ref> Later on, other major cryptocurrencies, such as [[Namecoin]] (an attempt at a decentralized [[domain name system|DNS]]), Litecoin (which uses scrypt as a proof-of-work, as well as having faster transaction confirmations) and PPCoin (which uses a proof-of-work/proof-of-stake hybrid, and has inflation of about 1%) were also created.<ref name="ars1" /> Many other cryptocurrencies have been created, though not all have been successful, especially those which brought very few new innovations.

For the first couple years of existence, cryptocurrencies gradually gained attention from the media and public,<ref>[http://www.technologyreview.com/review/425142/cryptocurrency/ Cryptocurrency], MIT Technology Review, 26-05-2013</ref> since 2011, interest has rapidly increased, especially during the rapid price rise of Bitcoin in April 2013.

==Proof-of-work schemes==
The most widely used proof-of-work schemes are [[SHA-256]], which was introduced by [[Bitcoin]], and [[scrypt]], which is used by currencies such as [[Litecoin]].<ref name="ars1" /> Some cryptocurrencies, such as [[PPCoin]], use a combined [[proof-of-work]]/[[proof-of-stake]] scheme.<ref name="PPCoin paper">{{cite web|title=PPCoin: Peer-to-Peer Crypto-Currency with Proof-of-Stake|url=http://www.ppcoin.org/static/ppcoin-paper.pdf|work=http://www.ppcoin.org/static/ppcoin-paper.pdf, 19-08-2012|publisher=Sunny King, Scott Nadal|accessdate=12-05-2013}}</ref><ref name="ars1" />

== List of cryptocurrencies==
''This is a list of the major cryptocurrencies, for a full list, see [[list of cryptocurrencies]].''
{| class="wikitable sortable"
|-
! Currency !! Symbol !! Year Est. !! Founder !! Active !! Ledger !! Website !! Value of [[money supply]] (May 2013) !! [[Bitcoin]]-based !! Note
|-
| [[Bitcoin]] || BTC || 2009 || Satoshi Nakamoto || {{yes}}<ref name="Bitcoin Exchange Rate">{{cite web|title=Bitcoin Exchange Rate in USD|url=http://bitcoincharts.com/charts/mtgoxUSD#rg60ztgSzm1g10zm2g25zv|accessdate=5 May 2013}}</ref> || [[Peer-to-peer|P2P network]] || [http://bitcoin.org bitcoin.org] ||~$1 billion [[USD]]<ref>{{cite web|title=Market Capitalization|url=http://blockchain.info/charts/market-cap|publisher=Blockchain.info|accessdate=21 March 2013}}</ref><ref name=MIT1 /> || {{yes}} || Decentralized ledger currency, [[SHA-256]] [[proof-of-work]]
|-
| [[Litecoin]] || LTC || 2011 || Coblee || {{yes}}<ref name="Litecoin Exchange Rate">{{cite web|title=Litecoin Exchange Rate in USD|url=https://btc-e.com/exchange/ltc_usd|accessdate=1 March 2013}}</ref> || [[Peer-to-peer|P2P network]] || [http://litecoin.org litecoin.org] || ~$38 million [[USD]]<ref name=MIT1 /> || {{Yes}} || [[Scrypt]] proof-of-work
|-
| [[Namecoin]] || NMC || 2011 || Vinced || {{yes}}|| [[Peer-to-peer|P2P network]] ||[http://dot-bit.org/Main_Page dot-bit.org]|| ~$4.5 million [[USD]]<ref>[http://dustcoin.com/mining Cryptocoin Mining Information], 18-05-2013</ref> || {{Yes}} || [[Decentralized]] [[Domain Name System|DNS]], SHA-256 proof-of-work
|-
| [[PPCoin]] || PPC || 2012 || Sunny King || {{yes}}<ref>{{cite web|title=PPCoin Exchange Rate in BTC|url=https://btc-e.com/exchange/ppc_btc|publisher=BTC-E}}</ref> || [[Peer-to-peer|P2P network]] || [http://ppcoin.org ppcoin.org] || ~$4 million [[USD]]<ref name=MIT1>{{cite web|last=Simonite|first=Tom|title=Bitcoin Isn’t the Only Cryptocurrency in Town|url=http://www.technologyreview.com/news/513661/bitcoin-isnt-the-only-cryptocurrency-in-town/|publisher=MIT Technology Review|accessdate=5 May 2013}}</ref> || {{Yes}} || SHA-256 proof-of-work/[[proof-of-stake]]
|-
|}

== Criticism ==
* Some people, such as bitcoin developer Gavin Andresen, have expressed concern that some of the other cryptocurrencies might be scams.<ref>Andresen, Gavin https://bitcointalk.org/index.php?topic=42465.0 (accessed 6 Apr 2013)</ref>

==See also==
* [[Digital currency]]
* [[Alternative currency]]
* [[Digital currency exchanger]]
* [[Cryptographic protocol]]
* [[Protocol of Bitcoin]]

==References==
{{Reflist}}

[[Category:Alternative currencies]]
[[Category:Application layer protocols]]
[[Category:Electronic currencies]]
[[Category:Payment systems]]
[[Category:Peer-to-peer computing]]
[[Category:Cryptography]]
[[Category:File sharing networks]]
[[Category:Distributed data storage‎]]
[[Category:E-commerce]]

Cryptocurrency - Revision history

wikademia>Eme: By: http://en.wikipedia.org/w/index.php?title=Cryptocurrency&action=history