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

The threat of quantum attacks on bitcoin has become more tangible as an independent researcher, Giancarlo Lelli, has been awarded a 1 bitcoin bounty for breaking a 15-bit elliptic curve key on publicly accessible quantum hardware. This achievement marks a significant milestone, being 512 times larger than the previous public demonstration in September 2025. The bounty, worth approximately $78,000, is the largest public demonstration of its kind and has significant implications for the security of bitcoin and other major blockchains. Elliptic curve cryptography, which is used to secure crypto wallets, is vulnerable to quantum attacks that could potentially derive private encryption keys from their public counterparts. While Lelli's achievement does not pose an immediate threat to bitcoin, which uses 256-bit elliptic curve security, it highlights the rapidly advancing field of quantum computing and its potential to challenge the security of cryptographic systems. The previous public break was a 6-bit demonstration, and Lelli's 15-bit result represents a significant expansion of this capability. Theoretical estimates suggest that the resource requirements for a full 256-bit attack are decreasing rapidly, with some estimates putting the cost below 500,000 physical qubits. This has significant implications for wallets with public keys already visible on-chain, with approximately 6.9 million bitcoin at risk. Developers have proposed migration paths, including the addition of quantum-safe address types, to mitigate this risk.