I've been using a handy little piece of software and I thought I'd share it with you all. I have a few USB thumb drives and a couple of portable hard drives. I'm always worried about losing one, and someone finding it and getting all my documents. Imagine if all those cute pictures of my cats made their way onto the web! After speaking to some of my nerd peers I decided to give TrueCrypt a try. TrueCrypt is Open Source encryption software. To use it, create a TrueCrypt volume on a drive. It just shows up like a document file. When you mount it with TrueCrypt you have to provide a password. Once you provide the correct password, TrueCrypt mounts the volume as a drive letter, so it's easy to use with any program inside of Windows. Here's a screenshot of TrueCrypt in action:
You can see that the T: drive on my system is mounted to the file E:\test. That file will only open if the appropriate password is entered. I've also highlighted an option in the menu "Traveller Disk Setup." This wizard walks you through setting up a removable disk to automount a TrueCrypt volume on it when it's attached to your computer. This makes using TrueCrypt very easy to use, even for someone unfamiliar with the software.
The performance is good. I haven't done any speed tests, but it's not noticeably slower than using the drive natively. I use this on all the external drives I carry back and forth to work. It gives me peace of mind knowing that if anyone should get a hold of one of my drives, they won't be able to get to any of my data.