Coinbase has begun designing custody infrastructure for approximately $250 billion in institutional assets that can support whichever post-quantum signature schemes Bitcoin or other blockchains eventually adopt. Chief Cryptographer Yehuda Lindell said the company is preparing for multiple outcomes because Bitcoin developers have not selected or activated a practical quantum-resistant signature standard, and different blockchain communities may choose different designs. The effort addresses a potential conflict between hash-based signatures and the Multi-Party Computation systems widely used to distribute control of private keys. Coinbase is also exploring programmable Hardware Security Modules that could assemble encrypted keys inside protected devices when a scheme cannot work with MPC. The company’s broader roadmap includes Bitcoin address changes, internal key-management updates and research into supporting ML-DSA within MPC infrastructure. Its planning follows work by Coinbase’s quantum advisory board and testing by BitGo of an ML-DSA-based quantum-safe MPC protocol. Bitcoin migration proposals, including BIP 360 and BIP 361, remain inactive, while the timing and design of any broader transition are unresolved.