Quantum hardware cracks 15-bit elliptic-curve key in public demo; Bitcoin's 256-bit security remains intact as migration clocks speed up

Huoxing Finance reported that Project Eleven has awarded today's QDay Prize to researcher Giancarlo Lelli after he derived a 15-bit elliptic-curve private key from its public key using publicly available quantum hardware. The result is the largest public demonstration of its kind so far, marking a 512-fold improvement over a 6-bit demonstration in September 2025. Lelli used a Shor's-algorithm variant adapted to the elliptic curve discrete logarithm problem (ECDLP), the mathematical basis of Bitcoin's signature scheme, running on hardware with roughly 70 qubits. Despite the milestone, no known quantum computer can break real Bitcoin wallets today; Bitcoin's 256-bit elliptic-curve security remains well beyond current quantum capabilities. Risk timelines are still being pulled forward. On March 31, Google reduced its resource estimates for ECDLP256 and set a post-quantum cryptography migration target for after 2029. Cloudflare has since taken a similar stance, and the UK's NCSC has outlined migration milestones spanning 2028 to 2035. On-chain data indicates around 6.93 million BTC may face potential quantum exposure because their public keys are already revealed. Within the Bitcoin community, BIP 360 and BIP 361 have been proposed to encourage quantum-resistant output types, though coordinating any network-wide shift across a decentralized system remains the central hurdle.