Coinbase is developing contingency plans to secure approximately $250 billion in client assets, including funds from BlackRock, against future quantum computing threats. The exchange’s current custody infrastructure relies on splitting private keys into shares to prevent single points of failure, but emerging hash-based post-quantum signatures may not support this key-splitting architecture. The potential incompatibility between standard post-quantum cryptographic methods and existing multi-party computation setups presents a significant technical challenge for institutional custodians. Coinbase is actively evaluating alternative backup solutions to ensure its security model remains viable as the industry transitions toward quantum-resistant cryptography.