{"id":35,"date":"2017-04-22T14:43:11","date_gmt":"2017-04-22T14:43:11","guid":{"rendered":"https:\/\/davidgerard.co.uk\/blockchain\/?page_id=35"},"modified":"2020-08-05T22:11:01","modified_gmt":"2020-08-05T22:11:01","slug":"buterins-quantum-quest","status":"publish","type":"page","link":"https:\/\/davidgerard.co.uk\/blockchain\/buterins-quantum-quest\/","title":{"rendered":"Buterin\u2019s quantum quest"},"content":{"rendered":"

Excerpt from chapter 9<\/a> of Attack of the 50 Foot Blockchain<\/a> by David Gerard<\/i><\/p>\n

Before founding Ethereum, Buterin put considerable effort in 2013 into trying to convince investors to fund him in constructing a quantum computer. (Note that no quantum computers able to solve practical problems are verified as existing as of early 2017.) His plan was to use this quantum computer to solve computationally infeasible problems that can\u2019t be done practically on an ordinary computer, such as reversing cryptographic hash functions.1<\/sup><\/a><\/p>\n

Since he didn\u2019t know how to build a quantum computer, his plan was to simulate<\/i> one on an ordinary computer \u2013 since this apparently wouldn\u2019t count as just running a program to solve the impossible problem. This was an idea that had long been put forward by Jordan Ash, his associate in this endeavour, who had put considerable effort into this startlingly crank mathematical notion.2<\/sup><\/a><\/p>\n

Buterin and Ash\u2019s plan was to use this simulated quantum computer not to revolutionise computation \u2013 but only to use it to mine bitcoins faster than anyone else and corner the market.<\/p>\n

Sadly for their Fields Medal hopes, they failed to secure sufficient funding to break mathematics. Investors may have been put off by the pointed questions from the crowd on how, quite apart from the mathematical implausibility, this would destroy any confidence in Bitcoin and kill the golden goose.<\/p>\n

It\u2019s also worth noting that a quantum computer would be able to solve the SHA-256 hash used in Bitcoin somewhat faster than an ordinary computer3<\/sup><\/a> \u2013 but it could also quickly break the public-key encryption that protects a user\u2019s Bitcoin balance. So if you secretly had a quantum computer, you could mine a bit faster, or<\/em> you could just steal everyone else\u2019s bitcoins.<\/p>\n

Buterin later said he had \u201cgreatly overestimated\u201d the likelihood of the team breaking mathematics, estimating this task at maybe 1% to 5% possible (apparently a purely subjective guess, with no basis given for even this number), and assures us that his skepticism concerning quantum claims has \u201csubstantially increased.\u201d He now puts the probability at \u201c<0.1%\u201d, though competent observers would likely consider even that on the high side for a mathematical impossibility.4<\/sup><\/a><\/p>\n

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1<\/a> \u201c<\/a>Vitalik\u2019s Quantum Quest\u201d<\/a>. Bitcoin Error Log<\/i> (blog), 16 August 2016.<\/small><\/p>\n<\/div>\n

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2<\/a> Jordan Ash. \u201cWhy Turing Machines are Quantum.\u201d<\/a> Noospheer<\/i> (blog), 4 September 2013. \u201cIf successful, it will have applications ranging from cryptography to finance, energy, medical care and beyond.\u201d<\/small><\/p>\n<\/div>\n

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3<\/a> O(sqrt(N)) rather than O(N), per Grover\u2019s algorithm<\/a>. Which is a pretty good speedup for as long as nobody else knows you have a quantum computer.<\/small><\/p>\n<\/div>\n

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4<\/a> Vitalik Buterin. Comment<\/a> on \u201cWhy does Greg Maxwell and many others from Bitcoin Core not respect Vitalik?\u201d Reddit \/r\/btc, 16 August 2016. (archive<\/a>)<\/small><\/p>\n<\/div>\n

 <\/p>\n

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Your subscriptions keep this site going. Sign up today!<\/a><\/i><\/p><\/div>","protected":false},"excerpt":{"rendered":"

How Vitalik Buterin planned to corner Bitcoin mining by simulating a quantum computer on a classical computer<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"inline_featured_image":false,"jetpack_post_was_ever_published":false,"footnotes":""},"class_list":["post-35","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/pages\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":9,"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/pages\/35\/revisions"}],"predecessor-version":[{"id":16917,"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/pages\/35\/revisions\/16917"}],"wp:attachment":[{"href":"https:\/\/davidgerard.co.uk\/blockchain\/wp-json\/wp\/v2\/media?parent=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}