Report: Physical Qubits Needed to Break Bitcoin Keys Could Drop to About 30,000

October 30: According to CoinDesk and The Quantum Insider, quantum computing company Alice & Bob has published research stating that, based on its cat qubit architecture, breaking the 256-bit elliptic curve key used by Bitcoin (ECDLP-256) would require about 29,588 physical qubits and roughly 62 minutes, cutting the required hardware by about 17 times compared with Google's March estimate of fewer than 500,000 qubits. Since that is still longer than Bitcoin's average block time of about 10 minutes, stealing funds before a transaction is confirmed remains difficult, but the more than 6 million BTC held in addresses whose public keys are already exposed face greater risk. The research remains a theoretical estimate; Alice & Bob expects hardware advances and falling resource requirements to converge in the early 2030s, and calls on Bitcoin to begin its quantum-resistant migration as soon as possible. In addition, the research estimates that breaking RSA-2048 would require about 22,593 physical qubits and 3.14 days.