keyrotation

Key rotation is the practice of periodically replacing cryptographic keys to limit the amount of data exposed by a single key and to minimize the impact of key compromise. It applies to symmetric keys, asymmetric keys, and credentials such as API keys and tokens. Regular rotation supports incident response, compliance with security standards, and the overall security lifecycle of cryptographic material.

In a rotation, a new key version is generated and becomes active while prior versions are retained for a deprecation period to allow decryption of existing data. Systems often use envelope encryption: data is encrypted with per-record data keys, and those data keys are themselves encrypted with a key-encryption key. When rotating, either the data keys are re-encrypted under a new key-encryption key, or the data keys are re-generated and wrapped by the current master key, depending on architecture. Key management systems and secret managers typically automate these steps, using schedules, event triggers, or usage-based rotation.

Key rotation introduces challenges such as ensuring uninterrupted access to data during transition, maintaining consistent key IDs, handling key history, revoking older keys, and preserving audit trails. It also requires proper access controls, secure storage of old keys, and coordination across services that rely on the keys. Designing rotation policies often involves defining key lifetimes, rotation frequency, and safety margins for critical systems.

Benefits of key rotation include reduced risk from key compromise, easier revocation of credentials, and stronger compliance with standards and audits. It is a core component of cryptographic lifecycle management alongside key generation, storage, usage, and retirement.