And of course, when you set up an encryption system to protect the security of your backup files, you must also set up a highly secure procedure for storing the encryption keys or the pass phrases that unlock them. Secret keys used to encrypt data should be stored in a safe or vault. Standard company practice needs to provide for the possibility that the employee handling this data could suddenly leave, die, or take another job. There must always be at least two people who know the storage place and the encryption/decryption procedures, as well as the policies for how and when keys are to be changed. The policies must also require that encryption keys be changed immediately upon the departure of any employee who had access to them.