Responding to a question about whether advancing quantum research puts Bitcoin at risk, Adam Back posted on X:
Quote from: Adam Back on November 15, 2025Probably not for 20-40 years, if then. And there are quantum secure signatures, NIST standardized SLH-DSA last year. Bitcoin can add over time, as the evaluation continues and be quantum ready, long before cryptographically relevant quantum computers arrive.
Back reframed the quantum threat as a solvable engineering problem with a multi-decade runway. Bitcoin Improvement Proposal 360 (BIP-360), drafted by Jameson Lopp, outlines a gradual transition to post-quantum-resistant outputs using NIST-standardized algorithms. As of 2025, the highest-capacity quantum systems remain far below the threshold needed to run Shor’s algorithm against Bitcoin’s elliptic curve signatures. This 20–40 year estimate is the timeline figure cited in the security model’s quantum threat section.
The quantum-threat analysis sets this 20–40 year estimate against the institutional timelines, including the NSA’s 2035 migration date.