TrueCrypt is an open-source disk encryption application that works for Windows, OS-X and Linux. It works by creating a virtual encrypted disk within a file and then mounting it as a real disk. You can write and read from the encrypted disk seamlessly as the encryption happens in real time, or on-the-fly so to speak.
You can choose from all that’s popular in crypto this year, AES-256, Serpent and my fave, Twofish, and the makers claim that it will allow data to be read and be written as fast as if the drive wasn’t encrypted. Just remember, if you forget the password your stuff is gone. At least until AES-256 and it’s kin get cracked. [Thanks Rogier]
TrueCrypt is a software system for establishing and maintaining an on-the-fly-encrypted volume (data storage device). On-the-fly encryption means that data is automatically encrypted or decrypted right before it is loaded or saved, without any user intervention. No data stored on an encrypted volume can be read (decrypted) without using the correct password/keyfile(s) or correct encryption keys. Entire file system is encrypted (e.g., file names, folder names, contents of every file, free space, meta data, etc).