Google Quantum AI paper (March 30–31, 2026) reframes Bitcoin's post-quantum timeline

A Google Quantum AI white paper dated March 30–31, 2026 argues that attacking Bitcoin-style elliptic curve cryptography could require far fewer quantum resources, sharpening focus on a 2029 migration target. The paper discusses scenarios including ~nine-minute key recovery from a broadcast transaction, a modeled 41% chance of pre-confirmation hijack, and estimates that about 6.9 million BTC (around 32% of supply) may be exposed when public keys are already revealed.