Researchers cracked a 15-bit ECC key and received a 1-bit Bitcoin reward.

Independent researcher Giancarlo Lelli has been awarded the Q-Day Prize and one Bitcoin by quantum security startup Project Eleven for successfully cracking the encryption key protecting Bitcoin. Lelli used publicly available quantum hardware and a variant of Shor's algorithm to crack the 15-bit encryption key out of 32,767 possibilities. This quantum attack is 512 times more difficult than the 6-bit key record set in September 2025. Project Eleven CEO Alex Pruden stated that the resource requirements for such attacks are declining, and approximately 6.9 million Bitcoins are currently in vulnerable static addresses, including 1 million held by Satoshi Nakamoto. The Bitcoin network has proposed BIP-360 to introduce quantum-resistant address types, and platforms such as Ethereum, Ripple, and Tron have begun releasing plans to transition to post-quantum defenses.