I need a free file encryption software

TrueCrypt is a simple, easy-to-use, on-the-fly encryption program. It works on Windows 2000/XP/2003 and Linux.

Some features include:

1. Ability to encrypt entire hard disk partition or a storage device
2. Creation of a virtual encrypted disk within a file that mounts as a real disk.
3. Encryption using AES-256, Blowfish (448-bit key), CAST5, Serpeant, Triple DES, and Twofish.

For a more information, please visit:
TrueCrypt