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

The threat of quantum attacks on bitcoin has become more tangible. Quantum security startup Project Eleven recently awarded a 1 bitcoin bounty, valued at approximately $78,000, to independent researcher Giancarlo Lelli. Lelli achieved this feat by breaking a 15-bit elliptic curve key on publicly accessible quantum hardware, thereby deriving a private encryption key from its public counterpart. This breakthrough is considered the largest public demonstration of its kind, posing a potential threat to bitcoin, ether, and other major blockchains. Elliptic curve cryptography, which enables crypto wallets to prove fund ownership without revealing private keys, is the primary target of quantum attacks. Quantum computers, utilizing Shor's algorithm, challenge the underlying security of these signatures. Although Lelli's achievement does not immediately compromise bitcoin's security, which relies on 256-bit elliptic curve security, it marks a significant milestone in the progression of quantum attacks on real-world cryptography-based products. The previous public demonstration, a 6-bit break by Steve Tippeconnic in September 2025, was surpassed by Lelli's result by a factor of 512 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 raises concerns, particularly for wallets with publicly visible keys, with approximately 6.9 million bitcoin at risk. In response, bitcoin developers have proposed migration paths, including the introduction of quantum-safe address types, while other cryptocurrencies like Ethereum, Tron, StarkWare, and Ripple have also published post-quantum transition plans.