I'm a system administrator and I use rsnapshot to backup some servers, duplicity for some others. Both work fine, each one with advantages and disadvantages. Despite that, I am at a loss on how to backup my own private files.

I'd use duplicity to automatically backup my files to a remote server; but the problem is that once in a while I must do a full backup. My emails and important files are 9G, and I expect this to increase. Uploading through aDSL at 1Mbit would be 20 hours. Too much.

rsnapshot doesn't require periodic full backups (only the first time), but it must be running on the remote server and have a means to connect to my computer; if the server is compromised (or simply if the NSA decides to use it), my own machine is also compromised. Not good.

The only solution I've come up with is use encfs, use unison to synchronize the files to a remote server, and use duplicity or rsnapshot on the remote server to backup these files. In that case, the question is whether I can sync the files on many computers; is it possible for encfs to be used with the same key on many computers? I also think that if I append one character to the unencrypted file, its encrypted encfs counterpart might change a lot, so that incrementals with duplicity would be less efficient—but not a big deal. Maybe also, when I need to restore a file, finding the correct file to restore could be a pain, because of filename encryption.

I wonder whether there is any other possibility that I've overlooked. Maybe I'm asking too much for my personal use, and I should settle with an external disk?