essay<\/a> published Monday, the Coin Metrics cofounder explains in plain language how bitcoin\u2019s keys work and why quantum matters. Carter writes that users start with a secret number (a private key) and derive a public key with elliptic-curve math on the secp256k1 curve, the basis for ECDSA and Schnorr signatures. <\/p>\nHe describes that transformation as deliberately one way: easy to compute forward, infeasible to reverse under classical assumptions. \u201cBitcoin\u2019s entire cryptographic premise is \u2018there exists a one-way function that\u2019s easy to compute in one direction, and infeasible to invert,\u2019\u201d he writes.<\/p>\n
To build intuition, Carter likens the system to a giant number scrambler. Going from private to public is efficient for honest users, he says, because they can use a shortcut known as \u201cdouble and add\u201d to reach a result quickly. He adds there is no comparable shortcut in the opposite direction. <\/p>\n
For non-specialists, he offers a deck-shuffle analogy: you can repeat the same sequence of shuffles to reach an identical final order, but an observer cannot look at the shuffled deck and infer how many shuffles were used.<\/p>\n
Carter argues the concern is that a sufficiently powerful quantum computer could erode that asymmetry by making progress on the discrete logarithm problem that underpins bitcoin\u2019s signatures. In his telling, routine network behavior also raises exposure: when coins are spent, a public key is revealed on-chain. <\/p>\n
He says that is safe today because converting a revealed public key back to the private key is not practical, but quantum advances could change that calculus, especially if addresses are reused and more keys remain visible for longer.<\/p>\n
He is not calling for panic. Carter says the point is to plan. <\/p>\n
Near term, he highlights basic hygiene such as avoiding address reuse so public keys are not exposed longer than necessary. Longer term, he urges the community to prioritize post-quantum signature schemes and realistic migration paths, framing them as engineering work rather than a distant thought experiment.<\/p>\n
The essay is the first in a short series; Carter said on X that parts II and III will arrive in the next couple of weeks and will cover \u201cpost-quantum break scenarios.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Nic Carter says quantum computing is the biggest long-term risk to bitcoin\u2019s core cryptography and urges developers to…\n","protected":false},"author":3,"featured_media":319182,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[7566,745,918,158,67,132,68],"class_list":{"0":"post-319181","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-computing","8":"tag-bitcoin","9":"tag-computing","10":"tag-quantum-computing","11":"tag-technology","12":"tag-united-states","13":"tag-unitedstates","14":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/115407866196001284","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/319181","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=319181"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/319181\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/319182"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=319181"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=319181"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=319181"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}