Quantum Attack Breaks 15-Bit Crypto Key, 512x Larger Than Last Record
A quantum computing breakthrough has alarmed the Bitcoin industry. Independent researcher Giancarlo Lelli used cloud-accessible quantum hardware to break a 15-bit elliptic curve key—512 times larger than the previous record set in September 2025.
Key Takeaway
Quantum attacks jumped 512x in seven months—Bitcoin's ₱48.56 trillion ($800 billion) vulnerable supply faces a shrinking timeline.
Independent researcher Giancarlo Lelli just performed the largest known quantum attack on elliptic curve cryptography, breaking a 15-bit key using cloud-accessible quantum hardware. Project Eleven, a startup focused on Bitcoin's quantum threat, awarded Lelli 1 Bitcoin for the breakthrough. Project Eleven CEO Andy Pruden said the resource requirements for this type of attack keep dropping, and the barrier to running it in practice is dropping with them.
That's 512 times larger than the previous record—a 6-bit key broken by Steve Tippeconnic in September 2025. The speed of progress has spooked the industry. Chaincode Labs estimates 60% of Bitcoin's supply is vulnerable to quantum attacks, putting ₱48.56 trillion ($800 billion) worth of coins at risk. That includes Satoshi Nakamoto's 1.1 million Bitcoin stash, which could be locked away if proposed quantum-exposure freezing measures take effect.
Luxor mining outlet CEO Nick Hansen put his worry level at six to seven on a ten-point scale. In January, BlackRock and UBS CEO Sergio Ermotti denounced the quantum threat—a shift from developers who had largely turned a blind eye. Google has accelerated its quantum timeline to 2029, while recent research from Google Quantum AI suggests fewer than half a million physical qubits may crack elliptic curve encryption in minutes.
Bitcoin miners face a separate crisis that could hamper quantum defense efforts. Mining became deeply unprofitable after the 2024 halving and the launch of Bitcoin ETFs in January 2024, which drained transaction fees. Bernstein analysts reported US miners are now migrating infrastructure to AI, diverting resources away from network security at the worst possible time. Lelli's attack came seven months after Tippeconnic's September 2025 demonstration—the first public proof of concept.
This article was written based on reporting from Dlnews.
