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 has successfully broken a 15-bit elliptic curve key on publicly accessible quantum hardware. The achievement, which earned the researcher a 1 bitcoin bounty worth roughly $78,000, demonstrates the largest public demonstration of this type of attack to date. The breakthrough was made possible by Project Eleven, a quantum security startup, which awarded the Q-Day Prize to Giancarlo Lelli for his accomplishment. Elliptic curve cryptography is a crucial component of bitcoin's security, enabling wallets to prove control over funds without revealing private keys. However, quantum computers pose a significant threat to this security, as they can potentially derive private keys from public ones using Shor's algorithm. While Lelli's achievement is significant, it does not mean that bitcoin is on the verge of being compromised, as the cryptocurrency uses 256-bit elliptic curve security, far more complex than the 15-bit key that was broken. The prize was designed to test the feasibility of quantum attacks on real-world cryptography-based products, and Lelli's result has expanded the previous public demonstration by a factor of 512 in just seven months. The previous public break was a 6-bit demonstration using IBM's 133-qubit quantum computer. 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. The concern is particularly significant for wallets with public keys already visible on-chain, with approximately 6.9 million bitcoin, roughly one-third of the total supply, potentially vulnerable to quantum attacks. Bitcoin developers have proposed migration paths, including BIP-360, to address this issue, while other cryptocurrencies, such as Ethereum and Ripple, have also published post-quantum transition plans.