To answer your original question, there are a number of programs that let you encrypt either the contents of a file, individual files, or entire drives. You just need to make sure that the encryption program can run on the operating systems of each computer you connect the removable drive to. PGP is well regarded option and, depending on your version and licensing, may include the option create an encrypted volume from a file. Just make sure it's secured with a password, not the key you want to encrypt in the first place...

There are a slew other options as well. One of my personal favorites is TrueCrypt (www.truecrypt.org) which is free, open source, runs on most operating systems. I use it to encrypt my USB thumb drive as well as things like financial documents on my PC.

Hope this helps.

J.

www.cert-tech.com