FreeOTFE is a free, open source, "on-the-fly" (OTFE) transparent disk encryption program.

Using this software, you can create one or more "virtual disks" on your PC - anything written to which will be automatically, and securely, encrypted before being stored.

Features include:

- Highly portable - Not only does FreeOTFE offer "portable mode", eliminating the need for it to be installed before use, it also offers FreeOTFE Explorer - a system which allows FreeOTFE volumes to be accessed not only without installing any software, but also on PCs where no administrator rights are available. This makes it ideal for use (for example) with USB flash drives, and when visiting Internet Cafs (AKA Cybercafs), where PCs are available for use, but only as a "standard" user.
- Source code freely available.
- Easy to use; full wizard included for creating new volumes.
- Data encrypted on your PC can be read/written on your PDA, and vice versa.
- 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: 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.
- Operates under both PC (MS Windows 2000/XP/Vista) and PDA (Windows Mobile 2003/2005/6) platforms.
- Linux compatibility (Cryptoloop "losetup", dm-crypt and LUKS supported).
- "Hidden" volumes may be concealed within other FreeOTFE volumes, providing "plausible deniability".
- Encrypted volumes can be either file or partition based.
- Modular design allowing 3rd party drivers to be created, incorporating new hash/cypher algorithms.
- Keyfile support included; store volumes and their associated metadata separately.
- Volume file timestamps and attributes are reset after dismounting, increasing "plausible deniability".
- Plus more...!