Quantum computers cracking 15-digit ECC keys pose no threat to Bitcoin's 256-bit security, but the migration countdown is accelerating.

ME News report: On April 25 (UTC+8), Project Eleven today awarded the Q-Day prize to researcher Giancarlo Lelli, who used publicly accessible quantum hardware to successfully derive a 15-bit elliptic curve private key from a public key—making it the largest public demonstration of its kind to date, improving by 512 times over the 6-bit demonstration in September 2025. Lelli used a variant of Shor’s algorithm targeting the elliptic curve discrete logarithm problem, which is the mathematical foundation of Bitcoin’s signature scheme. The awarded hardware has about 70 qubits. At present, there is no known quantum computer that can crack real Bitcoin wallets, and Bitcoin’s 256-bit elliptic curve security still remains far beyond current quantum capabilities. Worth noting is that on March 31, Google downgraded its resource estimate for ECDLP-256 and set a post-quantum cryptography migration target after 2029. Cloudflare followed suit immediately, and the UK NCSC has also set migration milestones from 2028 to 2035. On-chain data shows that currently about 6.93 million BTC face potential quantum risk because their public keys have been exposed. The Bitcoin community has proposed BIP 360 and BIP 361 to promote migration to quantum-resistant output types, but coordinating a decentralized network remains the biggest challenge. (Source: ChainCatcher)