Google’s Quantum AI team has proved that a sufficiently powerful quantum computer could derive a Bitcoin (BTC) wallet’s private key in approximately nine minutes, fast enough to intercept and redirect a transaction before it is confirmed on the blockchain in an estimated 41% of cases. Quantum computers’ attack speed vs network variance: Source: Google The research, published as a whitepaper co-authored with the Ethereum Foundation and Stanford University, estimates that cracking the elliptic curve cryptography protecting Bitcoin wallets may require fewer than 500,000 physical qubits, a roughly 20-fold reduction from prior published estimates. The researchers determined that a quantum attacker could extract a victim’s public key from the network’s mempool and apply Shor’s algorithm to derive the corresponding private key. Given Bitcoin’s average block confirmation time of approximately 10 minutes, a 9-minute quantum derivation window creates an overlap during which an attacker could complete the process before a transaction is finalised