Project Eleven, a research organization focused on quantum computing, has launched the Q-Day Prize, a global competition offering 1 Bitcoin to the first team or individual who can use Shor’s algorithm on a quantum computer to crack part of an elliptic curve cryptographic (ECC) key. This initiative aims to assess the real-world risk that quantum computing poses to Bitcoin’s security. The challenge targets the Elliptic Curve Digital Signature Algorithm (ECDSA). 10 million Bitcoin addresses have been exposed, potentially putting 6.2 million BTC worth $500 billion at risk if quantum technology continues to advance. The Q-Day Prize aims to move the discussion beyond theoretical speculation by encouraging a practical demonstration of vulnerability. To participate, teams must solely run Shor’s algorithm on a quantum computer without assistance from classical computing methods. Even breaking a few bits of an ECC key qualifies as a valid proof-of-concept and could indicate that full key recovery is possible with future technological advancements. This follows recent progress in the quantum computing sector, including Google’s ‘Willow’ chip, which recently performed calculations in five minutes that would take traditional supercomputers an estimated 10 septillion years to complete. Other leading companies such as IBM, Amazon, and Microsoft have also made advancements in quantum hardware. While real-world threats are not imminent, Project Eleven seeks to quantify the risk through open experimentation.