Quantum migration isn’t just a cryptography problem. It’s a coordination problem. Imagine a blockchain with millions of accounts. Some are active. Others are abandoned. Some users have lost their keys. Exchanges, institutions and smart contracts add further complexity. How do you migrate everyone to quantum-resistant cryptography? You need more than new algorithms: • Technology: Build and test new cryptographic systems. • Incentives: Encourage users to migrate. • Communication: Make the process clear and accessible. • Governance: Agree on timelines and network-wide changes. @tezos makes this challenge especially relevant as its ecosystem explores post-quantum readiness. Because upgrading cryptography is one challenge. Coordinating an entire ecosystem to adopt it is another. How should a blockchain handle accounts that never migrate: protect them indefinitely, restrict them eventually, or find another solution?