Google warns quantum computers could crack Bitcoin in 9 minutes

The crypto world has long treated its core mathematics as an unbreakable shield, viewing quantum threats as a problem for the distant 2040s.

Google just moved that timeline uncomfortably close.

Google researchers published a landmark paper warning that future quantum computers could crack the encryption protecting Bitcoin and Ethereum with far fewer resources than anyone thought. While confirming that no such machine exists today, Google urged the crypto industry to migrate to post-quantum cryptography by 2029.

The 9-minute crack and 1.7 million exposed coins

Blockchains like Bitcoin and Ethereum rely on 256-bit elliptic curve cryptography. Generating a public key from a private key is trivial, but reversing that process on classical supercomputers is practically impossible.

Google researchers built optimized quantum circuits tailored for this exact math, referencing advances seen in chips like Willow. Their findings show that breaking this encryption requires roughly 20 times fewer quantum resources than earlier models estimated.

When hardware requirements plunge by 95%, theoretical timelines shrink dramatically.

Under certain operational assumptions, the researchers estimate that private keys could be derived in approximately nine minutes. That is a terrifying number when compared to Bitcoin's average 10-minute block confirmation window.

When you broadcast a Bitcoin transaction, your public key is exposed while waiting in the mempool. If a quantum attacker can crack your private key in nine minutes, they could theoretically hijack the transaction and redirect funds before the block is mined.

Then there are dormant assets. Google highlighted that over 1.7 million Bitcoin sit in legacy address formats that openly expose public keys, including early mining rewards. Unlike active transactions, attackers wouldn't need to race the clock here; they could spend days or months calculating those keys offline.

Why it matters

For everyday crypto holders, there is no need to panic sell your portfolio today, but wallet hygiene is about to change. Anyone storing funds in legacy public-key addresses should prepare to migrate to modern, quantum-resistant schemes well before 2029.

For the blockchain industry, this paper turns a vague theoretical debate into a hard engineering deadline. Upgrading foundational cryptographic algorithms across decentralized networks requires contentious hard forks, multi-year consensus building, and massive smart contract retooling. Five years is barely enough time.

We think Google played this smartly. Instead of sensationalizing an immediate crypto apocalypse, it laid out rigorous math showing that algorithmic optimization can cut attack costs long before hardware fully matures.

The real risk lies in crypto governance inertia. Blockchains rarely coordinate massive breaking changes until disaster strikes at their doorstep. If developers treat 2029 as a casual suggestion rather than a strict expiration date, the industry could face an existential crisis the moment the first fault-tolerant quantum computer boots up.