County IT must encrypt multi-terabyte nightly backups for cold storage and separately assert agency identity when calling a partner court API. Which crypto method pairing best fits those two use cases?

Symmetric algorithms efficiently protect large data volumes when a shared secret can be managed, which suits bulk backup encryption. Asymmetric cryptography supports identity assertion, digital signatures, and key exchange with partners without pre-sharing the same long-term secret for every byte of payload. Selecting method classes by use case is a core CISSP cryptographic design skill.