a) Cryptoperiods
A cryptographic key is a value (essentially a random string of bits) that serves as input to an algorithm, which then transforms plain text into ciphertext (and vice versa for decryption). One of the important characteristics that determines key strength is its cryptoperiod [1]. Or the length of time for which the key is authorised for use.
Algorithm | Max Time | Average |
Hash |
2yrs 1.5yrs 2yrs |
1.8yrs |
Symmetric |
2yrs 2yrs 2yrs |
2 yrs |
Asymetric |
3yrs 3yrs 2yrs |
2.7 yrs |
The cryptoperiods suggested are only rough guidelines; longer or shorter cryptoperiods may be warranted, depending on the application and environment in which the keys will be used. However, when assigning a longer cryptoperiod than that suggested below, serious consideration should be given to the risks associated with doing so. Shorter is always better even though it might not be easier to apply. I would recommend the shortest time for each cryptoperiod because of the risks associated with longer periods
a) Cryptoperiods A cryptographic key is a value (essentially a random string of bits) that serves...
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