When must cryptographic keys be changed to ensure data security?

The requirement to change cryptographic keys at the end of their defined crypto period is essential for maintaining data security. Cryptographic keys are not meant to be used indefinitely because their effectiveness can degrade over time due to potential exposure to various threats and vulnerabilities. A defined crypto period is specified in cryptographic policies and procedures and is established based on factors like the sensitivity of the data being protected, the strength of the key, and the likelihood of it being compromised.

Changing keys at regular intervals ensures that even if a key were to be exposed or compromised, the potential impact is limited to the data encrypted with that specific key during its life span. This practice mitigates risks associated with key reuse and helps maintain the overall integrity of the encrypted information. A well-defined key management procedure will specify how often keys should be changed and under what circumstances, reinforcing the security posture of the organization handling sensitive data.