Double-spending Contents Prevention References Navigation menuThe Double Spending Problem and Cryptocurrencies"Digital Cash"0802.0832v1cs.CR10.1.1.120.5210.1109/ICDCS.2007.91"The Mission to Decentralize the Internet""Why Proof-of-work isn't suitable for small cryptocurrencies"e

Digital currenciesFinancial cryptographyPayment systemsInternet fraudDistributed computingCryptocurrencies


digital cashcounterfeit moneyinflationcirculationblind signaturessecret splittingBitcoinforksBitcoin Goldonlinetrusted third partysingle point of failuredistributed systemscryptocurrencybitcoincryptographic protocolproof-of-work systemledgerblockchain




Double-spending is a potential flaw in a digital cash scheme in which the same single digital token can be spent more than once. Unlike physical cash, a digital token consists of a digital file that can be duplicated or falsified.[1][2] As with counterfeit money, such double-spending leads to inflation by creating a new amount of copied currency that did not previously exist. This devalues the currency relative to other monetary units or goods and diminishes user trust as well as the circulation and retention of the currency. Fundamental cryptographic techniques to prevent double-spending, while preserving anonymity in a transaction, are blind signatures and, particularly in offline systems, secret splitting.[2]


A double-spending attack is a potential attack against cryptocurrencies that has happened to several cryptocurrencies, e.g. due to the 51% attack. While it hasn't happened against many of the largest cryptocurrencies, such as Bitcoin (with even the capability arising for it in 2014), it has happened to one of its forks, Bitcoin Gold, then 26th largest cryptocurrency.




Contents





  • 1 Prevention

    • 1.1 Centralized


    • 1.2 Decentralized



  • 2 References




Prevention


The prevention of double-spending attack has taken two general forms: centralized and decentralized.



Centralized


This is usually implemented using an online central trusted third party that can verify whether a token has been spent.[2] This normally represents a single point of failure from both availability and trust viewpoints.



Decentralized


By 2007, a number of distributed systems for the prevention of double-spending had been proposed.[3][4]


The cryptocurrency bitcoin implemented a solution in early 2009. It uses a cryptographic protocol called a proof-of-work system to avoid the need for a trusted third party to validate transactions. Instead, transactions are recorded in a public ledger called a blockchain. A transaction is considered valid when it is included in the blockchain that contains the greatest amount of computational work. This makes double-spending more difficult as the size of the overall network grows.[5] Other cryptocurrencies also have similar features.


Decentralized currencies that rely on blockchain are vulnerable to the 51% attack, in which a malicious actor can rewrite the ledger if they control enough of the computational work being done.[6]



References




  1. ^ The Double Spending Problem and Cryptocurrencies. Banking & Insurance Journal. Social Science Research Network (SSRN). Accessed 24 December 2017.


  2. ^ abc Mark Ryan. "Digital Cash". School of Computer Science, University of Birmingham. Retrieved 2017-05-27..mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"""""""'""'".mw-parser-output .citation .cs1-lock-free abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-subscription abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-ws-icon abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:inherit;padding:inherit.mw-parser-output .cs1-hidden-errordisplay:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintdisplay:none;color:#33aa33;margin-left:0.3em.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em


  3. ^ Jaap-Henk Hoepman (2008). "Distributed Double Spending Prevention". arXiv:0802.0832v1 [cs.CR].


  4. ^ Osipkov, I.; Vasserman, E. Y.; Hopper, N.; Kim, Y. (2007). "Combating Double-Spending Using Cooperative P2P Systems". 27th International Conference on Distributed Computing Systems (ICDCS '07). p. 41. CiteSeerX 10.1.1.120.52. doi:10.1109/ICDCS.2007.91.


  5. ^ Janus Kopfstein (12 December 2013). "The Mission to Decentralize the Internet". The New Yorker. Retrieved 30 December 2014. The network’s "nodes"—users running the bitcoin software on their computers—collectively check the integrity of other nodes to ensure that no one spends the same coins twice. All transactions are published on a shared public ledger, called the "block chain"


  6. ^ Varshney, Neer (2018-05-24). "Why Proof-of-work isn't suitable for small cryptocurrencies". Hard Fork | The Next Web. Retrieved 2018-05-25.









-

Popular posts from this blog

Moe incest case Sentencing See also References Navigation menu"'Australian Josef Fritzl' fathered four children by daughter""Small town recoils in horror at 'Australian Fritzl' incest case""Victorian rape allegations echo Fritzl case - Just In (Australian Broadcasting Corporation)""Incest father jailed for 22 years""'Australian Fritzl' sentenced to 22 years in prison for abusing daughter for three decades""RSJ v The Queen"

2009 crimes in AustraliaPeople convicted of incestRape in AustraliaChild abuse incidents and cases Victoria Police Moe, Victoria, Australiarapedphysically abusedviolencediedallegationsNews LimitedinvestigateMelbournedevelopmental problemsintellectually disabledspeech impedimentbirth certificateschargedsexual abuseDNA testspleadedguiltyincestindecent assaultcommon assaultsentencingimprisonmentparolesex offender registryappeal The Moe incest case emerged in February 2007 when a woman, identified as M for legal reasons, reported to Victoria Police in the town of Moe, Victoria, Australia that her 63-year-old father, RSJ, had raped, [1] [2] physically abused, and kept her a virtual prisoner in her own home between 1977 and 2005. Police had known about the alleged abuse since 2005, when M first came forward, but could not act because she did not want to cooperate after her father threatened violence against her mother and siblings. The J family had been known to authorities for more than ...
Read more

John Burke, 9th Earl of Clanricarde References Navigation menuA General and heraldic dictionary of the peerage and baronetage of the British EmpireLeigh Rayment's Peerage Pages

People from County GalwayJacobite military personnel of the Williamite War in IrelandHouse of Burke1642 births1722 deathsMembers of the Irish House of LordsEarls of ClanricardePeers of Ireland created by James II IrishpeerWilliam Burke, 7th Earl of ClanricardeRichardisle of InishbofinWilliamite War in IrelandBattle of AughrimUlick Burke, 1st Viscount GalwayProtestantsprivate act of the English ParliamentCatholicWild GeeseSpainBolognaFontenoyHonora BurkePatrick Sarsfield, 1st Earl of Lucan John Burke, 9th Earl of Clanricarde (1642–1722) was an Irish peer. Burke was a younger son of William Burke, 7th Earl of Clanricarde and succeeded his brother Richard. He was created Baron Bophin (over the isle of Inishbofin where Burke is still a common surname amongst the islanders [1] ) in 1689 and commanded a foot regiment as its colonel during the Williamite War in Ireland. He was taken prisoner at the Battle of Aughrim in 1691 and outlawed. His younger brother Ulick Burke, 1st Viscount G...
Read more

Football at the 1986 Brunei Merdeka Games Contents Teams Group stage Knockout stage References Navigation menu"Brunei Merdeka Games 1986".

Image
1986 in Asian footballFootball at the Brunei Merdeka Games1986 in Brunei1986 in Singaporean football1986 in Malaysian football1986 in Thai sport Bandar Seri BegawanBruneiMalaysia Cup Football at the 1986 Brunei Merdeka Games Tournament details Host country Brunei Dates 19 July – 27 July Teams 10 Final positions Champions Persib Bandung (1st title) Runners-up Malaysia B Third place   Brunei Fourth place Singapore XI Tournament statistics Matches played 10 Goals scored 25 (2.5 per match) ← 1985 1987 → The football tournament at the 1986 Brunei Merdeka Games was held from July 19 to 27 in Bandar Seri Begawan, Brunei. The tournament was also referred to as the Sultan Hassanal Bolkiah Cup, or the second Brunei Pesta Sukan Cup. Contents 1 Teams 2 Group stage 2.1 Group A 2.2 Group B 3 Knockout stage 3.1 Semi-finals 3.2 Bronze medal match 3.3 Gold medal match 4 References Teams It is likely that the Philippines team was the full national team, bu...
Read more