{"id":528,"date":"2026-01-26T10:00:00","date_gmt":"2026-01-26T09:00:00","guid":{"rendered":"https:\/\/kriptoblog.hu\/?p=528"},"modified":"2026-03-02T14:13:46","modified_gmt":"2026-03-02T13:13:46","slug":"kvantumszamitogepek-bitcoin-veszelyeben","status":"publish","type":"post","link":"https:\/\/kriptoblog.hu\/en\/kvantumszamitogepek-bitcoin-veszelyeben\/","title":{"rendered":"Quantum Computers: Is Bitcoin in Danger?"},"content":{"rendered":"<h2>Quantum computers and Bitcoin<\/h2>\n<p>A <strong>quantum computers'<\/strong> development regularly raises the question: <strong>is Bitcoin in danger?<\/strong> If a quantum computer were to break Bitcoin's cryptography, the entire system would collapse. But how realistic is this threat in 202<\/p>\n<h2>How could quantum computers threaten Bitcoin?<\/h2>\n<h3>1. Breaking ECDSA signatures<\/h3>\n<p>Bitcoin's <strong>Elliptic Curve Digital Signature Algorithm (ECDSA)<\/strong> cryptography is used. A sufficiently powerful quantum computer could, with <strong>Shor's algorithm<\/strong> theoretically extract the private key from the public key:<\/p>\n<ul>\n<li>This would enable spending other people's Bitcoins<\/li>\n<li>Particularly vulnerable are addresses whose <strong>public key is visible<\/strong> on the blockchain (old P2PK format, reused addresses)<\/li>\n<li><strong>Satoshi's ~1.1 million BTC<\/strong> is in such an old format<\/li>\n<\/ul>\n<h3>2. SHA-256 hash weakening<\/h3>\n<p>A <strong>Grover's algorithm<\/strong> speeds up hash search \u2013 but this is less critical:<\/p>\n<ul>\n<li>It would make mining more efficient but wouldn't break it<\/li>\n<li>The difficulty adjustment would compensate<\/li>\n<\/ul>\n<h2>Where does quantum technology stand?<\/h2>\n<h3>The current situation<\/h3>\n<ul>\n<li><strong>Google Willow (2024):<\/strong> 105-qubit chip that demonstrated \"quantum supremacy\" in specific tasks<\/li>\n<li><strong>IBM Condor:<\/strong> 1,121-qubit processor<\/li>\n<li>Breaking Bitcoin's ECDSA would require an estimated <strong>4,000-13,000 logical qubits<\/strong> (fault-tolerant qubits)<\/li>\n<li>Current machines use \"noisy\" qubits \u2013 the number of logical qubits is <strong>orders of magnitude lower<\/strong><\/li>\n<\/ul>\n<h3>Time Estimates<\/h3>\n<p>Expert estimates vary:<\/p>\n<ul>\n<li><strong>Optimistic (concerned):<\/strong> Breaking cryptography may be possible within 10-15 years<\/li>\n<li><strong>Conservative:<\/strong> 20-30+ years, if it's even possible at the required scale<\/li>\n<li><strong>NIST (US National Institute of Standards and Technology):<\/strong> The dangerous period could begin around 2035<\/li>\n<\/ul>\n<h2>Bitcoin's Defense<\/h2>\n<h3>Quantum-Resistant Cryptography<\/h3>\n<p>A <strong>NIST finalized in 2024<\/strong> the first quantum-resistant cryptographic standards:<\/p>\n<ul>\n<li><strong>CRYSTALS-Dilithium:<\/strong> Digital signature (lattice-based)<\/li>\n<li><strong>CRYSTALS-Kyber:<\/strong> Key exchange<\/li>\n<li><strong>SPHINCS+:<\/strong> Hash-based signature<\/li>\n<\/ul>\n<p>The Bitcoin community is planning the transition to <strong>post-quantum cryptography<\/strong> :<\/p>\n<ul>\n<li>Introducing a new quantum-resistant signature scheme via soft fork<\/li>\n<li>The Taproot upgrade paved the way for such extensions<\/li>\n<li>The migration will take years \u2013 but there's time<\/li>\n<\/ul>\n<h3>Immediate Defense<\/h3>\n<ul>\n<li><strong>Don't reuse addresses:<\/strong> If you only send from an address once, the public key is visible for a shorter time<\/li>\n<li><strong>P2TR (Taproot) addresses:<\/strong> The latest address format provides better protection<\/li>\n<li><strong>Cold storage:<\/strong> As long as you don't spend, the public key doesn't appear on the chain<\/li>\n<\/ul>\n<h2>Other Cryptocurrencies and the Quantum Threat<\/h2>\n<ul>\n<li><strong>Ethereum:<\/strong> Vitalik Buterin published a detailed plan for quantum-resistant transition<\/li>\n<li><strong>QRL (Quantum Resistant Ledger):<\/strong> A blockchain specifically designed to be quantum-resistant<\/li>\n<li><strong>IOTA:<\/strong> Ternary computing model with quantum-resistant ambitions<\/li>\n<\/ul>\n<h2>The Realistic Assessment<\/h2>\n<p>Before panicking, it's important to note:<\/p>\n<ul>\n<li>Quantum computers don't just threaten <strong>Bitcoin<\/strong> \u2013 the entire internet security (banks, military, communications) is based on the same cryptography<\/li>\n<li>If quantum machines reach that level, <strong>breaking Bitcoin will be the least of our worries<\/strong><\/li>\n<li>Bitcoin developers are working on the solution <strong>years ahead of the danger<\/strong> dolgoznak a megold\u00e1son<\/li>\n<li>The network's consensus mechanism makes it possible to update the cryptography<\/li>\n<\/ul>\n<h2>Summary<\/h2>\n<p>Quantum computers don't just threaten <strong>real but not immediate<\/strong> threat to Bitcoin. Technology development and the creation of post-quantum cryptography are progressing in parallel. The Bitcoin community has time to prepare \u2013 and is actively doing so.<\/p>\n<p><em>The quantum threat to Bitcoin is like climate change to society: real, long-term, and requires action \u2013 but the world isn't collapsing tomorrow.<\/em><\/p>\n<p><strong>\u26a0\ufe0f Legal disclaimer:<\/strong> This article is for informational purposes only and does not constitute investment advice. All investment decisions are made at your own risk.<\/p>\n<p><!-- IMAGE_PROMPT: Family Guy cartoon style illustration of Stewie Griffin in his lab with a massive quantum computer (glowing, futuristic, with floating qubits) trying to crack open a giant golden Bitcoin safe, but the safe keeps upgrading its lock every time he gets close, Peter Griffin duct-taping extra padlocks onto the Bitcoin safe labeled \"post-quantum crypto\", a countdown clock on the wall showing \"20+ years\" --><\/p>","protected":false},"excerpt":{"rendered":"<p>Kvantumsz\u00e1m\u00edt\u00f3g\u00e9pek \u00e9s a Bitcoin A kvantumsz\u00e1m\u00edt\u00f3g\u00e9pek fejl\u0151d\u00e9se rendszeresen felveti a k\u00e9rd\u00e9st: vesz\u00e9lyben van-e a Bitcoin? Ha egy kvantumg\u00e9p felt\u00f6rn\u00e9 a Bitcoin kriptogr\u00e1fi\u00e1j\u00e1t, az eg\u00e9sz rendszer \u00f6sszeomlana. De mennyire re\u00e1lis ez a vesz\u00e9ly 2026-ban, \u00e9s mit tehet ellene a k\u00f6z\u00f6ss\u00e9g? Hogyan fenyegethetik a kvantumg\u00e9pek a Bitcoint? 1. ECDSA al\u00e1\u00edr\u00e1sok felt\u00f6r\u00e9se A Bitcoin Elliptic Curve Digital Signature [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":568,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14,3],"tags":[21,4,127,114,29,141,147,113,56,136,129],"class_list":["post-528","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bitcoin","category-hirek","tag-banyaszat","tag-bitcoin","tag-biztonsag","tag-blockchain","tag-ethereum","tag-jovokep","tag-kvantumszamitogep","tag-satoshi-nakamoto","tag-sha256","tag-szabalyozas","tag-usa"],"_links":{"self":[{"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/posts\/528","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/comments?post=528"}],"version-history":[{"count":1,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/posts\/528\/revisions"}],"predecessor-version":[{"id":569,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/posts\/528\/revisions\/569"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/media\/568"}],"wp:attachment":[{"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/media?parent=528"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/categories?post=528"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kriptoblog.hu\/en\/wp-json\/wp\/v2\/tags?post=528"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}