What Happened to The QDay Prize (by Project Eleven)?

The QDay Prize, initiated by research firm Project Eleven, was conceived to accelerate open benchmarking of quantum cryptanalysis and raise public awareness about the potential threat quantum computers pose to widely used cryptographic standards, particularly Elliptic Curve Cryptography (ECC) securing cryptocurrencies like Bitcoin and Ethereum. The competition offered a substantial reward of 1 Bitcoin to the participant who could break the largest ECC key using Shor's algorithm on current quantum hardware.

On April 24, 2026, Project Eleven announced Giancarlo Lelli as the winner, awarding him 1 Bitcoin (valued at approximately $77,000 - $78,000 USD at the time) for successfully breaking a 15-bit ECC key on publicly accessible quantum hardware. This achievement was initially touted as a significant leap, representing a 512x increase from previous public demonstrations.

However, the prize's integrity and scientific merit were almost immediately called into question. On April 25, 2026, Craig Gidney, a leading quantum researcher at Google, published a scathing critique titled 'The predictable failure of the QDay Prize.' Gidney argued that the competition was fundamentally flawed, primarily because cryptographically relevant instances of Shor's algorithm necessitate quantum error correction, a capability largely absent in current quantum computers. He contended that the prize measured something irrelevant and that small problems could be 'solved' by luck rather than genuine quantum computational power. Gidney further alleged that the winning submission's results were indistinguishable from random guesses, suggesting a 'Falling with Style-style trick' rather than a true quantum attack.

The controversy intensified as other researchers echoed Gidney's concerns, with some noting that replacing quantum calls in the winning code with random calls yielded similar results. Critics argued that the QDay Prize, rather than raising legitimate awareness, had likely achieved the opposite, potentially damaging the credibility of efforts to benchmark quantum cryptanalysis. Project Eleven's CEO, Alex Pruden, acknowledged the criticism, admitting that the contest 'was certainly imperfect' and that 'small factoring problems are a very imperfect yardstick for Q-Day.' He defended the prize's intention to bridge the gap between theoretical quantum risk and public understanding, while also soliciting feedback for developing more effective open benchmarking methods.

As of April 28, 2026, the QDay Prize stands as a completed competition with an awarded prize, but its legacy is marred by significant scientific controversy. The debate highlights the ongoing challenges in accurately measuring and demonstrating quantum computing's progress in cryptanalysis, particularly in distinguishing genuine breakthroughs from artifacts of current hardware limitations or methodological flaws. Project Eleven is now focused on finding better ways to incentivize and benchmark quantum cryptanalysis, indicating a shift in approach following the widespread critique.