I used quite long time rdiff-backup for creating server backups. But I had to move away from it because it requires same program to run on the other end where backups are stored. And there was no chance that I can get it into 4Mib memory of my Asus router with OpenWrt which will now act as bacup server.
So I googled a bit and after reading several articles I decided to try duplicity. This decision was heavily inspired by article on Debian Administration website.
The setup with encryption and signing was very quickly and even restoring seems to work :-).