What is the recommended action for ensuring the longevity and security of cryptographic keys?

Backing up or escrow of cryptographic keys is crucial for maintaining their longevity and security. This practice ensures that in the event of loss or corruption of keys, they can be recovered, which is vital for accessing encrypted data or maintaining secure communications. By having a secure backup, organizations can prevent potential data loss and mitigate risks associated with having no access to important information when keys are compromised or lost.

The significance of key management extends beyond just backing up keys; it encompasses all aspects of key lifecycle management, including generation, distribution, storage, usage, and destruction. A robust backup strategy can help in disaster recovery scenarios and ensure operational continuity, which is why it stands out as a recommended action for maintaining cryptographic keys.

On the other hand, keeping keys too short compromises their security because shorter keys are more susceptible to brute-force attacks. Using only part of the keyspace for randomness is also a poor practice since it diminishes the potential combinations available, making the key easier to guess. Moreover, not destroying keys after their useful lifespan poses a risk of unauthorized access to sensitive data, as these keys could be exploited if they fall into the wrong hands.