How should cryptographic keys be rotated in field radios?

• A. Regularly, per policy, with secure distribution and storage.
• B. Only once at initial provisioning.
• C. Never rotate keys.
• D. Rotate by the operator randomly.

Answer: (A)

Rotating cryptographic keys on field radios on a regular, policy-driven schedule is essential to keep communications secure. By changing keys regularly, you limit the amount of data that could be decrypted if a key were ever compromised; the window of opportunity for an attacker remains small rather than indefinite. Following established procedures for distribution and storage ensures new keys reach the radios securely and that they are protected from tampering or unauthorized access once loaded. In practice, this means using approved fill devices or secure channels to load keys, verifying their integrity, and keeping auditable records of key lifetimes and updates.

Rotating only at initial provisioning leaves you with keys that could be used for a long time, increasing risk if they’re ever exposed. Never rotating keys keeps the system perpetually vulnerable to long-term exposure. Rotating randomly by the operator undermines coordination and policy compliance, potentially causing synchronization issues between communicating parties and breaking a controlled key lifecycle.