Google Quantum AI paper flags 6.9M Bitcoin as future quantum-risk target

A new whitepaper from Google Quantum AI estimates that about 6.9 million Bitcoin (BTC) could be exposed to future quantum "at-rest" attacks once quantum computers become sufficiently capable. The report says roughly 1.7 million BTC remains locked in legacy Pay-to-Public-Key scripts, where the public keys are permanently visible on-chain. The stash includes coins widely believed to be associated with Bitcoin's pseudonymous creator, Satoshi Nakamoto. No quantum system today can carry out such an attack. Google cautions that once the needed capability exists, these long-dormant holdings could be compromised without any new transaction being broadcast: an attacker could derive the private key directly from public blockchain data. The researchers add that a superconducting quantum computer could derive a Bitcoin private key in about nine minutes, narrowly within Bitcoin's average 10-minute block interval. Google describes the exposed supply as a "fixed, multibillion-dollar target" if protocol changes are not implemented in time. The paper also suggests governments explore legal frameworks for "digital salvage," treating dormant quantum-vulnerable coins similarly to unclaimed sunken treasure to keep them from being captured first by rogue states or criminal groups.