dup handler shouldn't require password set for encrypt key if no signature wanted
If one wants to backup (as root) user's data, that only needs to be encrypted, and not signed, then, AFAICT, there's no need for backupninja to check that a password is provided for the key.
With GPG asymetric encryption, you don't need some key's passphrase to be able to encrypt.
Of course it may be dangerous to encrypt without being able to decrypt, for instance to verify the backup's contents...
Hope this helps.
(from redmine: created on 2010-11-16)