Google: Bitcoin elliptic-curve keys need post‑quantum upgrades after tighter quantum-attack estimates

Google Research's new analysis finds quantum attacks on Bitcoin's elliptic-curve cryptography could require far fewer resources than earlier estimates — the paper reports a break could be feasible with under 500,000 qubits overall and that targeted attack strategies might need only about 1,200–1,450 high-quality qubits to compromise wallet security. The researchers also estimate a quantum attacker could intercept and redirect Bitcoin transfers in roughly nine minutes, and they flag Taproot's routine public-key exposure as expanding the vulnerability surface ^{[1] [2] [3]}.

Coverage of the research stresses that the findings tighten the timeline for when quantum threats to blockchains could become practical and have prompted calls within the industry for urgent adoption of post‑quantum cryptography to protect digital assets ^{[4] [5] [2]}.

Google frames the results as a future but nearer-than-expected risk and emphasizes responsible disclosure to give the cryptocurrency ecosystem time to evaluate mitigations and migrate to quantum-resistant protections ^[3].