When considering the migration of Bitcoin, selecting a post-quantum signature scheme is actually the least complicated step. A recent PQ paper published by Coinbase brings attention to a much more difficult issue. Wallets utilizing stateful schemes must carefully monitor exactly which one-time keys have already been utilized. Should a user restore an outdated backup and subsequently reuse a key, an attacker would then be able to successfully forge a valid signature.

https://www.coindesk.com/tech/2026/10/14/coinbase-which-holds-5-of-all-bitcoin-wants-the-quantum-fix-started-now