Use case for RSA encrypted backup key?

[carsten2]

The documenation says: "You can also use proxmox-backup-client key to create an RSA public/private key pair, which can be used to store an encrypted version of the symmetric backup encryption key alongside each backup and recover it later."

Without RSA I have to store the backup-key in a safe place.
With RSA I have to store the RSA-public/private key in a safe place.
Where is the difference?

What is the use case for this feature?

 

[t.lamprecht]

If you want to use more different keys you need to keep them all safe. But, if you use a master key you only need to keep a single key safe to protect many symmetric backup keys.
Also, you do not need to store the public key in a safe place, the whole idea of asymmetric encryption is that the public key can be, well, publicly available without any impact on security.

 

[carsten2]

If you want to use more different keys you need to keep them all safe. But, if you use a master key you only need to keep a single key safe to protect many symmetric backup keys.
Also, you do not need to store the public key in a safe place, the whole idea of asymmetric encryption is that the public key can be, well, publicly available without any impact on security.

I have to store the master private key AND the master key password which is much longer than the actuall encryption key. So I still dont' understand what the use case scenaria is, where the use of the RSA master encryption is useful instead of storing the actual encryption key.