FreeOTFE
FreeOTFE: A free "on-the-fly" transparent disk encryption program for MS Windows 2000/Windows XP.
Using this software, you can create one or more "virtual disks" on your computer - anything written to these disks is automatically, and securely, encrypted before being stored on your computers hard drive.
Features
Source code freely available
Easy to use; full wizard included for creating new volumes
Powerful: Supports numerous hash/encryption algorithms, and provides a greater level of flexibility than a number of other (including commercial!) OTFE systems
Hash algorithms include: MD5, SHA-512, RIPEMD-160, Tiger and many more
Cyphers include AES (256 bit), Twofish (256 bit), Blowfish (448 bit), Serpent (256 bit) and many more
"Portable mode" included; FreeOTFE doesn't need to be installed before it can be used - making it ideal for carrying your data securely on USB drives!
Operates under MS Windows 2000/Windows XP
Linux compatibility (Cryptoloop "losetup", dm-crypt and LUKS supported)
"Hidden" volumes may be concealed within other FreeOTFE volumes, providing "plausible deniability"
FreeOTFE volumes have no "signature" to allow them to be identified as such
Encrypted volumes can be either file or partition based.
Modular design allowing 3rd party drivers to be created, incorporating new hash/cypher algorithms
Decryption software available to improve transparency, and allow even the most junior software engineer to prove data is being encrypted correctly
Supports password salting (up to 512 bits), reducing the risks presented by dictionary attacks.
Allows users to backup and restore the critical areas of volume files.
Keyfile support included; store volumes and their associated metadata separately.
Uses per-sector IVs, including support for ESSIV
Volume file timestamps and attributes are reset after dismounting, increasing "plausible deniability"
Supports volumes files up to 2^63 bytes (8388608 TB)
Naturally, fully supported by SecureTrayUtil.
http://www.freeotfe.org/
Grand Dad