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 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 escalation in the scale of quantum attacks, with Lelli's result being 512 times larger than the previous public demonstration in September 2025. The bounty, worth approximately $78,000, was awarded by quantum security startup Project Eleven as part of its Q-Day Prize. Elliptic curve cryptography, which underpins the security of most major blockchains, including bitcoin and ether, relies on the difficulty of deriving a private key from its public counterpart. However, quantum computers running Shor's algorithm pose a significant threat to this security paradigm. Lelli's achievement does not imply that bitcoin is on the verge of being compromised, as it uses 256-bit elliptic curve security, but it does underscore the rapidly advancing capabilities of quantum attacks. The previous public break was a 6-bit demonstration, and Lelli's 15-bit result represents a substantial leap forward. 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 has significant implications for wallets with publicly visible keys, with Project Eleven estimating that roughly 6.9 million bitcoin are vulnerable to quantum attacks. In response, bitcoin developers have proposed migration paths, including the introduction of quantum-safe address types, while other cryptocurrencies, such as Ethereum and Ripple, have also published post-quantum transition plans.