OnLine Backup done safely and cheaply

A few posts back I wrote about a program called SuperFlexibleFileSynchronizer.

My latest project is to Scan all the papers in my file cabinet. That’s a little scarry. There’s information in there that I can’t afford to loose, yet most of it is private enough that I wouldn’t really trust it being stored online.

So today’s post talks about one possible solution for that, using Dropbox and SFFS.

Dropbox is a great online storage service. You put things in your local dropbox folder, and it copies them to the dropbox server. Dropbox has only one problem, and it’s a problem shared by any and all online backup systems: Security.

Call me an untrusting person, but I don’t trust that information put on Dropbox will stay private. It’s just too big a target for a hacker to avoid. At some point, it will be compromised. I feel this way about all online storage.

So what’s the solution?


Encrypt the data here, then put it on the Dropbox folder.

Now there are two ways to do this –
a) encrypt everything into a single file like a zip file or truecrypt volume
b) encrypt everything individually

The problem with a) is that you’d need to re-upload the entire file for every change, which isn’t really practical.

The problem with b) is that once the file is encrypted, it’s not as easy to compare the encrypted file, so incremental backups become an issue.

Enter SFFS. SFFS has an elegant solution to the problem. SFFS can make a backup where the folder structure is replicated, but each file is zipped with AES encryption. SFFS also keeps a signature for each file and puts it in the file name. In this way, SFFS is able to do incremental backups, comparing the unzipped originals to the zipped & encrypted copies.


For me.

To be clear: the names of the folders and files are visible, so if you’re dealing with super secret stuff, you’ll want to take that into account.

For my needs, I think it’s enough extra protection that I’m happy with it.

Now, if a hacker ever gets into dropbox, they’ll need to do some extra work to get into my files. Could they do this? Absolutely. Would they do this? Probably not. There would be so many other files that aren’t protected that my files wouldn’t be worth the hackers time.