A while back I wrote about Carbonite, a consumer PC online backup solution. I thought the user experience was fantastic, but I didn't love the idea that my data could be decrypted with just my (low-entropy) site password.
More recently, I decided to give Mozy a try. Mozy is another leading online backup app, and they offer 2 GB of personal backup for free. Interestingly, Mozy seemed to me to have the opposite qualities (both positive and negative) as Carbonite in my trial.
The security is hard-core if you choose: Mozy generates a 448-bit encryption key from any chunk of text or file that you give it. Naturally that means your source should have some decent entropy in it, and you'd better have a copy of either the key source material or the generated key file if you ever want your data back. But the folks who really want to keep their own key will know this already.
Mozy does encryption (and presumably decryption in a restore) locally, and ships the encrypted files off to storage. So your data is pretty darned safe from anyone inside or outside of Mozy.
The "average user" experience, though, had a number of annoying snafus.
The GUI on the client tool that manages your backups and filesets is neither pretty nor intuitive. I'm tempted to compare it to some of the more mediocre Gtk front ends to Linux command-line tools. Perhaps that's too harsh, but it does have a number of similar quirks, like multiple widgets that control the same setting without being clear about it, checkboxes becoming checked or unchecked "on their own", etc.
More troubling was that the client appears non-robust in the face of network outages. When the network dropped during my initial config, the app crashed. Upon restart, it did not appear to have saved state: I had to redefine my backup sets. I then started a backup, and the app crashed again when the network momentarily dropped. This time when I restarted it did have my backup sets, but the history window showed no trace of my failed backup.
Then, during my next backup attempt, after getting several hundred megabytes onto the net, my machine rebooted itself (courtesy of a Microsoft "patch Tuesday"). When I looked at Mozy, its history again showed nothing. I would have liked some information about the failed backup, and a way to "resume." Instead, I had to start the whole backup from byte 0.
This latter time, I achieved success. But in an era of WiFi access (which can be flaky), I would expect not only robustness in the face of network connectivity issues, but also a really solid resume mechanism. After all, how many machines will succeed with the initial multi-gig upload in one go?
To finish on a positive note, I should point out first that for paranoid^H^H^H^H^H^H^H^H security conscious people, it's great to have a tool that handles strong crypto inline and gives me control over the only key. Also, a quick search suggests Mozy is ready to bring out the heavy guns to address customer problems. If they keep that up, they'll be able to overcome almost anything else.