Researcher Claims 1 Bitcoin Bounty for Successful Quantum Attack on Elliptic Curve Key

The threat of quantum attacks on bitcoin has become more tangible after a researcher successfully broke a 15-bit elliptic curve key, a crucial component of the cryptocurrency's underlying technology. This achievement, made possible by quantum security startup Project Eleven's Q-Day Prize, has significant implications for the future of bitcoin and other major blockchains. The prize, worth approximately $78,000, was awarded to independent researcher Giancarlo Lelli, who used publicly accessible quantum hardware to derive a private encryption key from its public counterpart. Although this breakthrough does not immediately compromise bitcoin's security, which relies on 256-bit elliptic curve cryptography, it highlights the rapid progress being made in quantum attacks. Elliptic curve cryptography is the mathematical foundation that enables crypto wallets to verify fund ownership without exposing private keys. However, quantum computers, utilizing Shor's algorithm, pose a challenge to this assumption by targeting the underlying logic that secures these signatures. Lelli's achievement marks a significant milestone, expanding the previous public demonstration by a factor of 512 in just seven months. The previous record, set by Steve Tippeconnic in September 2025, involved breaking a 6-bit key using IBM's 133-qubit quantum computer. This recent advancement underscores the diminishing gap between theoretical attacks and practical demonstrations, prompting concerns about the long-term security of bitcoin and other cryptocurrencies. 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. Project Eleven CEO Alex Pruden noted that the barrier to running such attacks is also dropping, making it increasingly important for the cryptocurrency community to address these concerns. The winning submission, made by an independent researcher using cloud-accessible hardware, demonstrates that the capability to conduct such attacks is becoming more accessible. Approximately 6.9 million bitcoin, roughly one-third of the total supply, are stored in wallets with publicly visible addresses, making them potentially 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. Although the current achievement is still far from compromising bitcoin's 256-bit security, it serves as a reminder of the need for ongoing research and development to ensure the long-term security of cryptocurrencies.