Google Builds a Quantum Attack on Crypto Encryption, But Won’t Publish It

Google Quantum AI published a whitepaper showing it can break the elliptic curve cryptography protecting most blockchains using 20 times fewer resources than previously estimated.

The team, which includes Ethereum Foundation researcher Justin Drake and Stanford cryptographer Dan Boneh, refused to release the actual attack circuits. Instead, they published a zero-knowledge proof that allows anyone to verify the claim without learning how the attack works.

Why Google Hid the Code

Think of a blockchain wallet like a lock. The lock’s strength depends on a math problem called the Elliptic Curve Discrete Logarithm Problem (ECDLP-256).

Today’s computers would need billions of years to crack it. Quantum computers running Shor’s algorithm could do it in minutes.

Google’s researchers compiled two circuits for that attack. One uses fewer than 1,200 logical qubits and 90 million operations. The other uses fewer than 1,450 logical qubits and 70 million operations. Both can run on fewer than 500,000 physical qubits.

Previous estimates put the requirement at roughly 10 million physical qubits. Google just slashed that by a factor of 20.

The team chose to withhold the circuits because publishing them would hand attackers a blueprint.

Ryan Babbush, Director of Quantum Algorithms at Google, and Hartmut Neven, VP of Google Quantum AI, wrote that sharing resource estimates without the circuits follows established responsible disclosure norms.

What This Means for Crypto Holders

The paper warns that Bitcoin (BTC) alone has over 1.7 million BTC sitting in wallet formats where public keys are already exposed.

That figure could reach 2.3 million BTC when all vulnerable script types are counted.

Ethereum (ETH), Solana (SOL), and other chains face similar exposure through smart contracts, staking systems, and data availability mechanisms.

Google set a 2029 deadline for its own post-quantum migration. Haseeb Qureshi, managing partner at Dragonfly Capital, called the findings “serious” and warned that all blockchains need transition plans immediately.

Nic Carter, co-founder of Castle Island Ventures, called the paper “very sobering.”

The quantum clock is no longer theoretical. The question now is whether crypto can upgrade its locks before someone builds the key.

“…and the craziest thing is that the Google Quantum AI paper (above) is maybe not even the most concerning quantum paper released _today_,” warned Carter.