Coinbase council urges crypto developers to start post-quantum migration now

Coinbase’s Quantum Advisory Council said Bitcoin and other crypto networks should begin planning for post-quantum migration before quantum attacks become practical, arguing that the biggest challenge is not only technical implementation but also deciding how to handle coins that are never moved to safer formats. The council said roughly 7 million BTC are quantum-vulnerable because public keys are already exposed through legacy address formats or through address reuse, including about 1.7 million BTC in legacy Pay-to-Public-Key addresses tied to early mined, potentially lost or abandoned coins. The report said no existing quantum computer can break the cryptography protecting crypto assets today, but warned that decentralized networks often need years to coordinate major upgrades involving wallets, exchanges and user funds. That makes early preparation important even without an immediate threat. The council outlined several policy paths for vulnerable coins that are not migrated. One option would impose a deadline after which exposed funds could be frozen or burned, prioritizing network protection but raising property-rights concerns. Another would leave those coins untouched, preserving ownership claims but risking eventual theft if quantum capabilities advance. It also discussed middle-ground approaches including rate limits on spending from older addresses through an "hourglass" mechanism and zero-knowledge proofs such as BIP-361 that could let users prove control of old keys without exposing sensitive information. The report’s practical recommendation was to separate engineering work from the governance debate: build and test quantum-safe signatures now, while continuing to debate how lost, abandoned or otherwise unmigrated coins should be treated later.