Is there an easy way to have the backups encrypted at rest? That's a nice feature of Duplicity. I don't have to worry about someone hacking my backup server or borrowing my USB drive having access to my data.
currently bup doesn't implement encryption (since it's a pretty hard feature to get right and we do want to finish coding other key features -- like old backup removal -- before we get to that)
some ppl have reported using an encrypted storage backend like ecryptfs to store their bup repositories in. that option shouldn't be too hard to put together.
