Google’s Quantum AI Lowers Bitcoin Quantum Attack Threshold: BTC/ETH Post-Quantum Rush

Google’s Quantum AI team warns that Bitcoin quantum security may be undermined with fewer quantum resources than previously assumed. In a new white paper, researchers argue that quantum computers could crack the elliptic-curve cryptography used by BTC and ETH sooner and with significantly lower qubit requirements than earlier estimates. The paper cites scenarios where roughly 1,200–1,450 high-quality qubits could be sufficient, rather than needing hundreds of thousands of physical qubits. For Bitcoin, the risk is tied to a transaction-level exposure window: if a sufficiently powerful quantum computer exists, attackers may reconstruct the private key from the briefly visible public key, enabling an “on-spend” style attack. For Ethereum, the threat is framed as more structural because public keys are visible after an account’s first transaction, allowing “at-rest” style compromises. The report also notes an estimated probability of public-key-to-private-key recovery by 2032 and discusses a mass-compromise scenario for top accounts. Google says it targets moving its authentication systems to post-quantum cryptography by 2029, but the implication for Bitcoin quantum security and broader crypto infrastructure is clear: wallets, validators, and payment providers may face pressure to upgrade earlier to avoid exposure during the transition. Market takeaway for traders: this is a narrative catalyst for BTC/ETH security repricing, with potential short-term volatility around “quantum risk” headlines and longer-term focus on post-quantum migration readiness across networks like SOL.