Google Quantum AI Proves Breaking Crypto Encryption Needs 20x Fewer Resources Than Previously Estimated

Google Quantum AI shows breaking crypto encryption needs 20x fewer qubits than estimated, setting a 2029 post-quantum migration deadline for all blockchains.

Google Quantum AI Proves Breaking Crypto Encryption Needs 20x Fewer Resources Than Previously Estimated Google Quantum AI shows breaking crypto encryption needs 20x fewer qubits than estimated, setting a 2029 post-quantum migration deadline for all blockchains. Aaron Rafferty April 02, 2026 Key Takeaways: Google Quantum AI published a whitepaper showing its implementation of Shor's algorithm can break ECDSA-256 with fewer than 1,200 logical qubits and roughly 500,000 physical qubits, a 20x reduction from prior estimates. Google set a 2029 deadline for its own post-quantum cryptography migration, compressing a timeline the industry previously placed in the mid-2030s. Ethereum has an active post-quantum migration roadmap across four planned hard forks. Bitcoin has no equivalent coordinated effort. Google Quantum AI published a whitepaper on March 30 showing that the quantum computing resources needed to break the encryption protecting Bitcoin, Ethereum, and most major blockchains are roughly 20 times smaller than previously estimated. The research team, which includes Ethereum Foundation researcher Justin Drake and Stanford cryptographer Dan Boneh, compiled two quantum circuits implementing Shor's algorithm against the 256-bit elliptic curve discrete logarithm problem (ECDLP-256), the mathematical foundation of ECDSA signatures used by virtually every major blockchain. The first circuit uses fewer than 1,200 logical qubits and 90 million Toffoli gates. The second uses fewer than 1,450 logical qubits and 70 million Toffoli gates. In practical terms, Google estimates the attack could be executed in minutes on a machine with fewer than 500,000 physical qubits , down from roughly 10 million in prior estimates compiled between 2017 and 2023. That number is worth sittin