Stellar has deployed a post-quantum signature scheme on its mainnet, with Protocol 30 introducing an ML-DSA host function designed for smart wallets. The implementation makes Stellar one of the early adopters of quantum-resistant cryptography among major Layer 1 networks. At the Meridian conference, Tomer Weller outlined Stellar's broader quantum roadmap to Cami Russo. A key milestone scheduled for next year will enable classic accounts to rotate their signing keys without changing their account address or losing existing DeFi positions — addressing a long-standing concern that post-quantum transitions could fragment liquidity and break composability across protocols.