Google Says The End Of Bitcoin Is Near? Quantum Computers Could Attack Crypto Soon
It sounds like something out of a sci-fi video game, but new research suggests that quantum attackers can break the Bitcoin blockchain and steal coins during transactions faster than originally thought.
Is Doomsday Near For Bitcoin?
A new white paper and blogpost published on Tuesday by the Quantum AI team of Google says that the cryptography of Bitcoin and Ethereum can be broken in less than 500,000 physical qubits and about 1,200 “logical” qubits, much less than the “millions” that were often mentioned.
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Most blockchains and cryptocurrencies protect wallets and transactions using 256‑bit elliptic curve cryptography (the strongest mathematical key) based on the clear logarithm problem (ECDLP-256). Research scores are significantly lower in resources needed to complete ECDLP-256. The blog post says:
We estimate that these circuits can be made on a superconducting qubit CRQC with less than 500,000 physical qubits in a few minutes, given general assumptions about the hardware capabilities of some of Google’s flagship quantum processors. This is about a 20-fold reduction in the number of qubits needed to solve ECDLP-256 and a continuation of a long history of gradual improvements in integrating quantum algorithms into fault-tolerant circuits.
“Cryptographically-relevant quantum computers (CRQS) are a threat to widely used public key encryption”, the white paper says. Instead of attacking wallets, research shows a live attack where a quantum adversary can steal a bitcoin transaction within about 9 minutes by quickly using a briefly exposed public key to calculate a private key, giving a 41% chance of beating Bitcoin’s 10-minute blocking time. In this sense, Ethereum may be less vulnerable than Bitcoin, as it guarantees its transactions faster.
Culprit: Taproot
These results put Taproot, the Bitcoin development of 2021, in a different light. Although Taproot increased privacy and efficiency, it began exposing public keys to the -chain automatically, removing the “hash-first” security layer that older address formats had. Therefore, he expanded the collection of exposed quantum coins to about 6.9 million BTC, including the Satoshi era and the most reused addresses.
A quantum computer is a computer that uses the laws of quantum physics to process information in ways that ordinary computers cannot. Instead of bits that can be 0 or 1, it uses qubits, which can be 0, 1, or a combination of both at the same time, allowing the machine to test multiple possibilities in parallel. Early computers evaluated the possibilities one by one (even if they were very fast). This means that, for certain mathematical problems (such as entering large numbers used in cryptography), a powerful quantum computer can solve in minutes what would take a classical supercomputer longer than the universe’s years.
What This Means for Concerned Traders
While it’s true that no such machine exists yet, earlier this month Google set 2029 as the internal deadline for the post-quantum migration, pushing the supposed “Q-day” timeline. Researchers warn that the post-quantum migration will take years, even if the hardware is not yet there.
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On the X forum, some users have already expressed their quantum panic. Coin Metric founder and Bitcoin advocate Nic Carter highlighted another paper released today from Oratomic, Caltech and UC Berkeley, which shows quantum computers can break crypto with only 10,000 reconfigurable atoms.
and the saddest thing is that the Google Quantum AI paper (above) is probably not even the most influential quantum paper released _today_
– nic carter (@nic_carter) March 31, 2026
About one-third of Bitcoin’s supply is now modeled as potential exposure over a long enough horizon, which could change the way desks value old coins, taproot use and address-reuse hygiene. Traders should look at Taproot acquisition metrics, progress or gridlock around BIP‑360‑style development, and whether Bitcoin devs are going on the current migration plan as Google’s 2029 clock looms large.
At the moment of writing, BTC trades for the highs $66k. Source: BTCUSD on Tradingview
Cover image from Perplexity, BTCUSD chart from Tradingview
