FileVault: Lessons Learned

September 1, 2008

As a long-time fan of Apple, I have been enjoying my MacBook since Christmas. It has opened to me an entirely new world of productivity and connectivity, being able to get on the internet and do work nearly anywhere. Wrap this potency in an aesthetically pleasing white shell and blue interface and you have a favorite toy. Having not used a Mac for several years prior, I am very happy with Leopard, the current Mac operating system. Built atop Unix, Leopard finally accomplishes what the Open Source movement has long sought to do -- build a nice interface on the most powerful operating system in existence.

Among Leopard's add-on features is File Vault. It is a program by Apple, part of the core system, designed to protect your files from anyone who might seek illicit access. It encrypts your home folder. In other words, it uses the power of math to lock up your files, making sure that only someone with the special key can open them. When you log in as a user, it asks for your password and unlocks the files. When you log out or shut down, it locks the files up again. The files are not just hidden behind a password like they are on most systems. The files themselves are scrambled, and only the password can unscramble them.

Or, at least, it is supposed to be able to unscramble them. In my case, not so much. I had been working on my research, and traveling had prevented my making convenient backups for two weeks. One otherwise fine day, while my research-writing FileVaulted account was open, my MacBook failed to shut down properly. The encryption didn't properly lock back up, and I could not get back into that account. Eight hours later, my other accounts on the MacBook were fine, and now FileVault free, but the account with my research was entombed under a broken encryption mess.

When I went to the Apple Store, the geniuses there told me that FileVault should not be used. I really wish that I was told that before it made my writing into an omelet.

The lesson? Security measures that hurt you more than any potential malicious user are not security at all.