--- title: Alice & Bob Estimates 22,593 Qubits to Break RSA-2048 description: Alice & Bob estimates that breaking RSA-2048 with Shor's algorithm would require 22,593 physical cat qubits and 3.14 days on fault-tolerant superconducting... canonical: https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Alice & Bob Estimates 22,593 Qubits to Break RSA-2048 | daily.dev og:description: Alice & Bob estimates that breaking RSA-2048 with Shor's algorithm would require 22,593 physical cat qubits and 3.14 days on fault-tolerant superconducting... og:url: https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l og:image: https://api.daily.dev/og/posts/79Cinhu9l.png og:image:alt: Alice & Bob Estimates 22,593 Qubits to Break RSA-2048 og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Alice & Bob Estimates 22,593 Qubits to Break RSA-2048 **[The Quantum Insider](https://daily.dev/sources/thequantuminsider)** · 5 min read · 0 upvotes · 0 comments ## Summary Alice & Bob estimates that breaking RSA-2048 with Shor's algorithm would require 22,593 physical cat qubits and 3.14 days on fault-tolerant superconducting hardware. That's 40 times fewer qubits than Google researcher Craig Gidney's 2025 estimate. Attacking the 256-bit elliptic-curve discrete logarithm problem, which underpins Bitcoin and Ethereum's ECDSA, would need 29,588 qubits and 61.8 minutes. The gains come from LDPC-cat codes, which cut the RSA-2048 qubit count from a prior 49,649 to 22,593, plus a redesigned adder. These are theoretical resource estimates, not demonstrated attacks, and Alice & Bob recommends organizations start migrating to post-quantum cryptography now. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How many qubits would it take to break RSA-2048 with Shor's algorithm? Alice & Bob estimates 22,593 physical cat qubits running for 3.14 days on fault-tolerant superconducting hardware. This is about 40 times fewer physical qubits than Google researcher Craig Gidney's 2025 estimate, achieved through LDPC-cat error-correcting codes and a redesigned adder, cutting the prior cat-qubit estimate from 49,649 qubits. _Security teams timing their post-quantum migration can track quantum hardware milestones like this on daily.dev._ ### How many qubits would it take to break 256-bit elliptic curve cryptography like Bitcoin's ECDSA? An estimated 29,588 physical cat qubits running for 61.8 minutes could attack the 256-bit elliptic-curve discrete logarithm problem underlying ECDSA and ECDH. For Bitcoin specifically, that runtime exceeds the network's 10-minute block time, so transactions already in progress would remain safe from such an attack even under this projection. _Developers weighing elliptic-curve versus post-quantum schemes can follow research like this on daily.dev._ ## Similar posts on daily.dev - [Quantum Computers Are Coming to Break Cryptography Faster Than Anyone Expected](https://daily.dev/posts/quantum-computers-are-coming-to-break-cryptography-faster-than-anyone-expected-h97rgmcky) · Singularity Hub · 35 upvotes · 3 comments - [IonQ Estimates 20,000-Qubit Machine Could Break Bitcoin’s secp256k1 in 26 Days](https://daily.dev/posts/ionq-estimates-20-000-qubit-machine-could-break-bitcoin-s-secp256k1-in-26-days-johsziubp) · The Quantum Insider · 4 upvotes · 1 comments - [From RSA to Lattices: The Quantum Safe Crypto Shift](https://daily.dev/posts/from-rsa-to-lattices-the-quantum-safe-crypto-shift-nhaaxiasc) · IEEE Spectrum · 0 upvotes · 0 comments - [Why Haven’t Quantum Computers Factored 21 Yet?](https://daily.dev/posts/why-haven-t-quantum-computers-factored-21-yet--inmhkl0p3) · Hackaday · 1 upvotes · 0 comments --- Tags: [#quantum-computing](https://daily.dev/tags/quantum-computing), [#cryptography](https://daily.dev/tags/cryptography) [View this post on daily.dev](https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Alice \u0026 Bob Estimates 22,593 Qubits to Break RSA-2048","url":"https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l"},"datePublished":"2026-10-29T15:12:51.063Z","dateModified":"2026-10-29T15:23:37.742Z","description":"Alice \u0026 Bob estimates that breaking RSA-2048 with Shor's algorithm would require 22,593 physical cat qubits and 3.14 days on fault-tolerant superconducting...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2c99eb926b1151a6e4ec5aa672df5420?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2c99eb926b1151a6e4ec5aa672df5420?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"The Quantum Insider","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"The Quantum Insider","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/7b14a6b34c1b464c9e8a88d9a0dac951","url":"https://daily.dev/sources/thequantuminsider"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"quantum-computing,cryptography","timeRequired":"PT5M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"The Quantum Insider","item":"https://daily.dev/sources/thequantuminsider"},{"@type":"ListItem","position":3,"name":"Alice \u0026 Bob Estimates 22,593 Qubits to Break RSA-2048"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/alice-bob-estimates-22-593-qubits-to-break-rsa-2048-79cinhu9l#faq","mainEntity":[{"@type":"Question","name":"How many qubits would it take to break RSA-2048 with Shor's algorithm?","acceptedAnswer":{"@type":"Answer","text":"Alice \u0026 Bob estimates 22,593 physical cat qubits running for 3.14 days on fault-tolerant superconducting hardware. This is about 40 times fewer physical qubits than Google researcher Craig Gidney's 2025 estimate, achieved through LDPC-cat error-correcting codes and a redesigned adder, cutting the prior cat-qubit estimate from 49,649 qubits. Security teams timing their post-quantum migration can track quantum hardware milestones like this on daily.dev."}},{"@type":"Question","name":"How many qubits would it take to break 256-bit elliptic curve cryptography like Bitcoin's ECDSA?","acceptedAnswer":{"@type":"Answer","text":"An estimated 29,588 physical cat qubits running for 61.8 minutes could attack the 256-bit elliptic-curve discrete logarithm problem underlying ECDSA and ECDH. For Bitcoin specifically, that runtime exceeds the network's 10-minute block time, so transactions already in progress would remain safe from such an attack even under this projection. Developers weighing elliptic-curve versus post-quantum schemes can follow research like this on daily.dev."}}]} ```