It sounds out of a sci-fi video game, but new research suggest quantum attackers could break Bitcoin’s blockchain and steal coins mid-transaction sooner than it was originally expected. Is Doomsday Near For Bitcoin? A new whitepaper and blogpost published on Tuesday by Google’s Quantum AI team claims that Bitcoin and Ethereum’s cryptography can be broken with fewer than 500,000 physical qubits and roughly 1,200 “logical” qubits, far below the “millions” that used to be cited. Related Reading: Hyperliquid’s Tokyo Edge Exposed — Secret Time Gap Is Tilting The Market Most blockchains and cryptocurrencies protect wallets and transactions using 256‑bit elliptic curve cryptography (a very strong mathematical lock) based on the discrete logarithm problem (ECDLP‑256). The research points at a significant decreased in the resources needed to break the ECDLP-256. The blog post says: We estimate that these circuits can be executed on a superconducting qubit CRQC with fewer than 500,000 physical qubits in a few minutes, given standard assumptions about hardware capabilities that are consistent with some of Google’s flagship quantum processors. This is an approximately 20-fold reduction in the number of physical qubits required to solve ECDLP-256 and a continuation of a long history of gradual optimization in compiling quantum algorithms to fault-tolerant circuits. “Cryptographically-relevant quantum computers (CRQS) pose a threat to widely deployed public-key cryptography”, the whitepaper claims. Instead of attacking wallets, the research models a live attack where a quantum adversary could steal bitcoin mid‑transaction in about 9 minutes by quickly using the briefly revealed public key to calculate the private key, giving a 41% chance of beating Bitcoin’s 10‑minute block time. In this sense, Ethereum might be less vulnerable than Bitcoin, as it confirms its transactions faster. The Culprit: Taproot This results put Taproot, Bitcoin’s 2021 upgrade, in a different perspective. Although Taproot boosted privacy and efficiency, it started exposing public keys on‑chain by default, stripping away the “hash-first” protective layer that older address formats had. Therefore, it has widened the pool of quantum‑exposed coins to about 6.9 million BTC, including Satoshi‑era and heavily reused addresses. A quantum computer is a computer that uses the rules of quantum physics to process information in ways normal computers can’t. Instead of bits that are either 0 or 1, it uses qubits, which can be 0, 1, or a blend of both at the same time, letting the machine explore many possibilities in parallel. Classical computers explore possibilities one‑by‑one (even if very fast). This means that, for certain math problems (like factoring huge numbers used in cryptography), a powerful quantum computer could solve in minutes what would take a classical supercomputer longer than the age of the universe. What This Means For Concerned Traders Despite it is true that no such machine exists yet, earlier this month Google set 2029 as an internal deadline for post‑quantum migration, compressing the perceived timeline for “Q‑day.” Researchers warn that post-quantum migration will take years, even if the hardware is not here yet. Related Reading: Over Half Of US Crypto Users Don’t Understand This Scary Tax Rule On the social network X, some users have already expressed their quantum panic. Coin Metric co-founder and Bitcoin advocate Nic Carter highlighted another paper released today from Oratomic, Caltech and UC Berkeley, showing quantum computers can break crypto with just 10,000 reconfigurable atomic qubits. and the craziest thing is that the Google Quantum AI paper (above) is maybe not even the most concerning quantum paper released _today_https://t.co/mSZi5Lk7do — nic carter (@nic_carter) March 31, 2026 Roughly one‑third of Bitcoin’s supply is now modeled as potentially quantum‑exposed over a long enough horizon, which could change how desks value old coins, Taproot usage and address‑reuse hygiene. Traders should watch for Taproot adoption metrics, progress or gridlock around BIP‑360‑style upgrades, and whether Bitcoin devs move toward a dated migration plan as Google’s 2029 clock ticks louder. At the moment of writing, BTC trades for the highs $66k. Source: BTCUSD on Tradingview Cover image from Perplexity, BTCUSD chart from Tradingview
Concerns over quantum computing are weighing on Bitcoin’s price and slowing some investment flows, amid a sharp divide between developers and many investors. Related Reading: UK Crypto Ownership Takes Biggest Hit Since 2021, Regulator Says Developers Call Threat Distant According to Bitcoin developer Adam Back of Blockstream, quantum machines remain far from able to break Bitcoin’s protections. He said the tech is still “ridiculously early” and that research hurdles persist. Back expects no real threat within the next decade and argued that even if parts of Bitcoin’s cryptography were compromised, the network would not automatically be emptied. Security, he noted, does not rest solely on encryption in a way that would allow mass theft on the blockchain. i think the risks are short term NIL. this whole thing is decades away, it’s ridiculously early and they have massive R&D issues in every vector of the required applied physics research to even find out if it’s possible at useful scale. but it’s ok to be “quantum ready” and — Adam Back (@adam3us) December 18, 2025 The Risk That Keeps Some Awake Other voices in the community disagree. Jameson Lopp, a well-known Bitcoin engineer, has warned about the worst-case outcome if quantum advances allowed attackers to break the ECDSA signature scheme that secures many wallets. In that scenario, forged signatures could be used to move funds, and user confidence might erode quickly. That warning has been repeated as a technical possibility, not as something imminent. How should we treat quantum vulnerable coins in a future where quantum computing becomes a threat? This panel from the Presidio Quantum Bitcoin Summit features myself, @theblackmarble, and @cryptoquick.https://t.co/jhr6hjLXru — Jameson Lopp (@lopp) September 14, 2025 Investors Worry, Capital Shifts Nic Carter, a partner at Castle Island Ventures, told observers that it is “extremely bearish” when influential developers appear to dismiss any quantum risk outright. He said the gap between investor concern and developer assessment is large. Reports have disclosed that some capital is being held back while large holders consider spreading risk into other assets. Craig Warmke of the Bitcoin Policy Institute added that perceived quantum risk has already pushed some holders to reduce their Bitcoin positions. Quantum risk is stemming the flow of capital into bitcoin, and encouraging large holders to diversify out of bitcoin. When non-technical people express concerns, they sometimes use technically incorrect language. It’s frustrating to see technical people dismiss concerns with an… https://t.co/MtSNY7Ivg3 — Craig Warmke (@craigwarmke) December 18, 2025 Current Technology Falls Short Most cryptographers agree quantum computers today are not powerful enough to crack Bitcoin’s cryptography. That assessment is widely reported by analysts who follow both fields. Metaculus’s median date for when quantum computers will break modern cryptography is 2040:https://t.co/Li8ni8A9Ox Seemingly about a 20% chance it will be before end of 2030. — vitalik.eth (@VitalikButerin) August 27, 2025 Still, the timeline is debated. Based on reports from researchers and public comments from industry figures like Vitalik Buterin, there is a measurable chance — about ~20% — that a machine capable of breaking today’s crypto could exist by 2030. That estimate has prompted calls for proactive steps. Related Reading: Trump-Linked World Liberty Backs USD1 With Treasury-Fueled Expansion Calls For Preparedness Grow Financial institutions and national programs, the reports say, are investing heavily in quantum work, and tools like AI are accelerating research in the field. As a result, many in the crypto world argue contingency plans should be ready well before any practical threat appears. Suggestions include moving to quantum-resistant signature schemes and improving wallet practices so funds are not left exposed while upgrades take place. Some experts point out that banks and other big targets may face attacks earlier, which could give the crypto sector time to respond. Featured image from Shutterstock, chart from TradingView
Microsoft has recently rolled out a chip called Majorana 1 that its engineers say could point the way to building quantum computers with the scale people once only imagined. Google and IBM have also posted progress updates in recent months, and some in crypto called the news alarming. Related Reading: Ethereum Faith Fading? Samson Mow Says Holders Will Shift To Bitcoin But Graham Cooke, a Google veteran-turned blockchain CEO, pushed back on the panic, saying “Your wallet’s math is stronger than the fabric of spacetime itself.” Majorana 1 And The Million Qubit Claim Microsoft says Majorana 1 uses a new class of material — a “topoconductor” — and an architecture meant to make qubits more stable and easier to scale toward a million-qubit device. The company frames the chip as a step toward practical, fault-tolerant quantum machines that could handle very large problems. That kind of scale is what makes some people worry about cryptography, because certain quantum algorithms work very differently from the classical math that protects keys today. Microsoft built a 1-million-qubit quantum computer. Bitcoin holders are panicking—this could crack crypto encryption. But your seed phrase has 340,000,000,000,000,000,000,000,000,000,000,000,000 combinations. Here’s why quantum still can’t touch it: pic.twitter.com/kiI5oIXej1 — GC Cooke (@GCcookeHQ) August 11, 2025 Google’s Willow And IBM Roadmaps Based on reports, Google’s Willow chip and IBM’s public roadmap have added fuel to the conversation. Google showed a chip that it says solved a benchmark task in under five minutes that, by their measure, would take a classical supercomputer roughly 10 septillion years. IBM has published plans for staged systems — Starling and later Blue Jay — to push toward many logical qubits and extensive error correction over the next several years. Those announcements mean companies are getting closer to solving long-standing engineering problems, but they do not equal an instant ability to undo modern cryptography. Why Bitcoin Isn’t Facing A Panic Right Now Cryptography experts point out that breaking Bitcoin’s elliptic-curve keys needs not just more physical qubits but stable, error-corrected logical qubits and huge run-times. Estimates vary widely, but respected analysis has shown that breaking a 256-bit elliptic curve in a practical time window would require millions or at least many hundreds of thousands of physical qubits once error correction is counted. In short: the path from a lab milestone to a machine that can target Bitcoin addresses at scale still runs through a lot of hard engineering. A 24-word seed phrase? That’s 340 septillion trillion MORE combinations than a 12-word phrase. We’re approaching 10^77 possibilities – nearly as many as atoms in the observable universe (10^80): — GC Cooke (@GCcookeHQ) August 11, 2025 Related Reading: Chainlink Tipped To Outshine XRP In Global Banking Links: Analyst Seed Phrases And Dizzying Numbers Based on reports and public comments from practitioners, wallet math is not the whole story but it matters. Cooke has stressed how large a 24-word seed phrase keyspace is compared with a 12-word phrase, and he used big-picture comparisons — like saying the universe’s age of 14 billion years and “a trillion trillion” restarts — to show how vast those numbers are. Featured image from Getty Images, chart from TradingView
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