Cryptoperiod

A cryptoperiod is the time span during which a specific cryptographic key is authorized for use. Common government guidelines range from 1 to 3 years for asymmetric cryptography, and 1 day to 7 days for symmetric cipher traffic keys.

Factors to consider include the strength of the underlying encryption algorithm, key length, the likelihood of compromise through a security breach and the availability of mechanisms of revoking keys.