Final answer:
To enable a user or group to read encrypted files they did not encrypt, you should share the encryption key with them and potentially add them to the access control list for those files.
Step-by-step explanation:
To allow a user or group the ability to read encrypted files which they themselves did not encrypt, you would need to share the encryption key with the user or group.
This process involves giving the necessary permissions to access the private key used for decrypting the files. If a system uses an access control list (ACL), you might also need to add the user or group to the ACL of the encrypted files so that their account is granted read permissions.