The perceived threat of quantum attacks to Bitcoin's security has become more tangible with the recent achievement of independent researcher Giancarlo Lelli. Lelli was awarded 1 bitcoin, valued at approximately $78,000, by quantum security startup Project Eleven for breaking a 15-bit elliptic curve key on publicly accessible quantum hardware.
This breakthrough represents the largest public demonstration of its kind, outpacing the previous record by a factor of 512. Elliptic curve cryptography is crucial in enabling cryptocurrency wallets to verify fund ownership without exposing private keys. However, the advent of quantum computers running Shor's algorithm poses a significant challenge to this cryptographic method. Although Lelli's achievement does not immediately compromise Bitcoin's security, which relies on 256-bit elliptic curve security, it underscores the rapidly advancing capabilities of quantum attacks.
The previous public demonstration, achieved by Steve Tippeconnic in September 2025 using a 6-bit key, has been eclipsed by Lelli's 15-bit result, marking a substantial leap in just seven months. The implications of this breakthrough are far-reaching, with estimates suggesting that roughly 6.9 million bitcoin, approximately one-third of the total supply, are potentially vulnerable to quantum attacks due to their public keys being visible on-chain.
In response, Bitcoin developers have proposed migration plans, including the introduction of quantum-safe address types, while other cryptocurrencies like Ethereum, Tron, StarkWare, and Ripple have also outlined their post-quantum transition strategies.