Breakthrough in Quantum Attack: Researcher Claims 1 Bitcoin Bounty

The threat of quantum attacks on cryptocurrency 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 512-fold increase from the previous public demonstration in September 2025. Elliptic curve cryptography, which enables crypto wallets to prove control over funds without revealing private keys, is the foundation of most major blockchains, including Bitcoin and Ethereum. However, quantum computers running Shor's algorithm pose a significant challenge to this security measure. While Lelli's breakthrough does not pose an immediate threat to Bitcoin, which uses 256-bit elliptic curve security, it highlights the rapidly advancing field of quantum attacks. The previous public break was a 6-bit demonstration, and Lelli's result expanded this by a factor of 512 in just seven months. Theoretical estimates suggest that the resource requirements for a full 256-bit attack are decreasing, with a recent Google Research paper estimating the cost to be below 500,000 physical qubits. This raises concerns for wallets with public keys already visible on-chain, with approximately 6.9 million bitcoin sitting in such addresses. To address this, Bitcoin developers have proposed migration paths, including the introduction of quantum-safe address types. The broader community, including Ethereum, Tron, StarkWare, and Ripple, has also published post-quantum transition plans.