[GnuPG-users] identical files -> non-identical encrypted files

[Kiss Gabor (Bitman)]

> I have a local file that I want to encrypt and upload to a remote
> machine in encrypted form.  Encrypting is farily quick, but uploading is
> slow, so I use rsync for the other (unencrypted) files.  But the fact
> that the encrypted file is different each time defeats the rsync
> incremental upload.
> 
> A partial workaround is only encrypting when the plaintext file is newer
> than the encrypted one, but it's not bulletproof because sometimes the
> plaintext _does_ get saved even if it's identical.
> 
> Not a huge deal, in all, but someone must have faced this situation before.

Jari Ruusu's loop-aes uses the following method:
- it encrypts disk/file with AES 
- it has 1-65 pieces of 128-256 bit keys for this symmetric cipher
- disk keys are stored in a file that is encrypted by GPG
- Several users may have access to this file (each with his own secret key)

So I suggest to use some similar way.
Loop-aes utility 'aespipe' does the above key handling automagically.

Gabor