If Quantum computer cracks Bitcoin encryption 1BTC… ‘Q-Day’ competition opens

The quantum computing company Project Eleven has launched a global competition offering 1 Bitcoin to find the world's first challenger to decrypt the Bitcoin encryption system.

This competition, named the ‘Q-Day Prize’, aims to decrypt the elliptic curve cryptography (ECC) protecting the Bitcoin network using Shor’s Algorithm on a quantum computer. Participants can register individually or as teams and can receive 1 BTC (currently about 84,000 dollars) as a prize if they complete the task by April 5, 2026.

Shor’s Algorithm allows for the rapid solution of large-scale integer factorization, which is impossible for classical computers, in a quantum environment. Theoretically, traditional encryption algorithms like ECC or RSA can be broken by this method.

Project Eleven explained, “Public keys have already been exposed in over 100,000 Bitcoin addresses,” and “in fact, assets worth over 6 million BTC, approximately 500 billion dollars, are at risk.” While no ECC key used in reality has been broken so far, they added, “If even a small key is decrypted, it would be a landmark event in the history of cryptography.”

Participants must use only pure quantum computation, and classical algorithms or hybrid methods are not allowed. Project Eleven has opened up realistic possibilities, stating “Even breaking 3 bits would be big news.” Cloud-based quantum computing provided by Amazon Web Services (AWS) or IBM can also be utilized.

Currently, IBM’s Heron chip is at 156 qubits, and Google's Willow is at 105 qubits, which is still insufficient to decrypt a 256-bit ECC key, but Project Eleven predicts, “A 2,000-qubit quantum system could emerge within the next 10 years.”

The Bitcoin community also recognizes these threats. In early April, a Bitcoin Improvement Proposal (BIP) called ‘QRAMP (Quantum-Resistant Address Migration Protocol)’ was proposed for a network-wide transition to a quantum-resistant address system. However, this involves a hard fork, and it is widely recognized within the industry that reaching consensus is challenging.

Meanwhile, quantum startup BTQ has suggested a new proof-of-work alternative called ‘CGBS (Coarse-Grained Boson Sampling).’ This method replaces mining puzzles with photon patterns, also requiring a hard fork.

Cryptocurrency security expert Jameson Lopp mentioned in March, “No one can definitively say how severe the quantum computer threat is now,” but added, “Because Bitcoin is a system difficult to change, it is time for serious discussion.”

Tether CEO Paolo Ardoino also commented, “Concerns are valid,” but “ample preparation can be made before a real threat emerges.”