Quantum researcher cracks 15-bit ECC key on public hardware — 512x bigger than last record, and Bitcoin's clock is ticking!

Independent researcher Giancarlo Lelli has broken a 15-bit elliptic curve key using publicly accessible quantum hardware, winning Project Eleven's 1 BTC Q-Day Prize — worth roughly $78,000 — in the largest public demonstration of a quantum attack on cryptographic systems to date. The result is 512 times larger than the previous record set just seven months ago, when a 6-bit key was broken using IBM's 133-qubit machine.

The feat is still far from threatening Bitcoin's 256-bit elliptic curve security — a 15-bit key has only 32,767 possible values — but the trajectory is what's alarming. A Google Research paper published last month put the physical qubit cost of a full 256-bit break below 500,000, down from estimates in the millions just years ago. 'The resource requirements for this type of attack keep dropping, and the barrier to running it in practice is dropping with them,' said…