How long can a CIK stay in the TKL before losing information?

• A. 2 hours
• B. 4 hours
• C. 6 hours
• D. 8 hours

Answer: (B)

A CIK stored in the TKL is kept only for a limited window to protect the key material. The TKL is designed to hold temporary cryptographic keys for a short duration, and four hours is the maximum time the CIK can remain there before it is erased or invalidated. This rotation minimizes the risk if the radio is compromised or memory is exposed, by ensuring keys don’t stay usable for too long. After four hours, the system clears the CIK, so the information cannot be recovered and must be reloaded for continued secure operation. Longer retention would increase exposure risk, while shorter retention would disrupt operations, which is why four hours is the correct policy.