@virgil , can you clarify if you are referring to Hardware Encryption (from the library itself), or Commvault’s software encryption?

• For Hardware Encryption, the vendor would be the best resource for impact.
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• Hardware Encryption allows you to encrypt data on tape drives that have built-in encryption capabilities. Hardware encryption provides considerably faster performance than software encryption.
• Several tape drives like LTO4 or higher support encryption of data on the tape drive. These tape drives provide the necessary controls to the backup applications to get the encryption capabilities as well as set the encryption properties on the drive. Some of tape libraries also provide key management services. Commvault's Hardware Encryption feature provides key management for the tape libraries that do not support key management by themselves.

https://documentation.commvault.com/11.24/expert/7794_hardware_encryption.html

For more on the CV management of the keys, check out this doc:

https://documentation.commvault.com/11.24/expert/7813_hardware_or_library_management_of_encryption_keys.html

CV is able to handle the key management if the vendor does not.