Researcher Claims 1 Bitcoin Bounty for Achieving Largest Quantum Attack on Underlying Technology

The theoretical threat of quantum attacks on bitcoin has become more tangible. Quantum security startup Project Eleven awarded its 1 bitcoin Q-Day Prize to Giancarlo Lelli, who broke a 15-bit elliptic curve key on publicly accessible quantum hardware. This achievement is considered the largest public demonstration of a potential threat to bitcoin and other major blockchains. Elliptic curve cryptography, which enables crypto wallets to prove fund control without revealing private keys, is being challenged by quantum computers running Shor's algorithm. Although Lelli's result does not pose an immediate threat to bitcoin, which uses 256-bit elliptic curve security, it highlights the progress being made in quantum attacks on real-world cryptography-based products. The previous public break was a 6-bit demonstration, and Lelli's 15-bit result represents a 512-fold increase in just seven months. Theoretical estimates suggest that the resource requirements for a full 256-bit attack are decreasing rapidly, with a recent Google Research paper estimating the cost to be below 500,000 physical qubits. This development has significant implications for wallets with visible public keys, with approximately 6.9 million bitcoin at risk. In response, bitcoin developers have proposed migration plans, including the introduction of quantum-safe address types, while other cryptocurrencies like Ethereum and Ripple have also published post-quantum transition plans.