Disk encryption software

Disk encryption is a computer security technique that encrypts data stored on a computer's mass memory and automatically decrypts the information when an authorized user requests it. Disk encryption systems intercept operating system read and write operations and carry out the appropriate cryptographic transformations without any special action by the user except supplying a password or pass phrase at the beginning of a session. Disk encryption can apply to a directory or an entire disk volume.

Disk encryption is paricularly suited to portable devices such as laptop computers and key drives. If used properly, someone finding a lost device will only have acess to meaninless encrypted files. A strong pass phrase (e.g. six or more diceware words) is recommended for adequate security.

Common disk encryption software includes:

• PGPDisk from the makers of Pretty Good Privacy [1]
• FileVault which is built into Apple's OS-X operating system.