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FreeOTFE and FreeOTFE4PDA |
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| Developer(s) | Sarah Dean | ||
| Stable release | v5.10 / October 13, 2009 | ||
| Operating system | Linux, Microsoft Windows and PocketPC | ||
| Available in | English, Spanish, German, French, Italian, Czech and Japanese | ||
| Type | Transparent disk encryption | ||
| License | Open source[1] | ||
| Website | www.FreeOTFE.org | ||
FreeOTFE is an "on-the-fly" disk encryption (OTFE — On the Fly Encryption) program for PCs running MS Windows and Windows Mobile PDAs (FreeOTFE4PDA). It creates "virtual disks" - anything written to which is automatically encrypted before being stored on the computer's hard drive or USB drive.
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Overview
FreeOTFE was initially released by Sarah Dean in 2004, and was the first open source disk encryption system that provided a modular architecture allowing 3rd parties to implement additional algorithms if required.
This software is compatible with Linux encrypted volumes (e.g. LUKS, cryptoloop, dm-crypt), allowing data encrypted under Linux to be read (and written) freely. It was the first open source transparent disk encryption system to support Windows Vista and PDAs [2]
Optional two-factor authentication using smart cards and/or hardware security modules (HSMs - also known as security tokens)[3] was introduced in v4.0, using the PKCS#11 (Cryptoki) standard developed by RSA Laboratories.
FreeOTFE also allows any number of "hidden volumes" to be created, giving plausible deniability and deniable encryption, and also has the option of encrypting entire partitions or disks[4]
Portable Use
Unlike most disk encryption systems, FreeOTFE can be used in "portable mode", which allows it to be kept on a USB drive or other portable media, together with its encrypted data, and carried around. This allows it to be used under Microsoft Windows without installation of the complete program to "mount" and access the encrypted data through a virtual disk.
In common with other disk encryption systems which offer a "portable" (or "traveller") mode, the use of this mode requires installing device drivers (at least temporarily) to create virtual disks, and as a consequence administrator rights are needed to start this traveller mode. Because the drivers used do not have a Microsoft signed digital signature, under Windows Vista x64 and Windows 7 x64 systems the user must enable test signing[5].
Driverless Operation
The author of FreeOTFE also offers another program called "FreeOTFE Explorer"[6] which provides a driverless system that allows encrypted disks to be used without administrator rights.
This allows FreeOTFE encrypted data to be used on (for example), library computers or computer kiosks (interactive kiosks) where administrator rights are not available.
Unlike FreeOTFE, FreeOTFE Explorer does not provide on-the-fly encryption through a virtual drive[6]. Instead it works in a similar manner as some archiving software in that it allows files to be stored and extracted from encrypted disk images, in a similar manner as ZIP and RAR archives - though using a Windows Explorer interface.
Algorithms implemented
Due to its architecture, FreeOTFE provides great flexibility to the user with its encryption options.
Ciphers
There are a number of ciphers implemented in FreeOTFE, including:
All of the NIST AES finalists are included in FreeOTFE, and all of the ciphers can be used with multiple different keylengths
Cipher modes
Originally FreeOTFE offered encryption using CBC with ESSIV, though from v3.00 introduced LRW and also the more secure XTS mode, which supersedes LRW in the IEEE P1619 standard for disk encryption.
Hashes
As with its cipher options, FreeOTFE offers many different hash algorithms:
References
- ^ Previous versions of FreeOTFE required that any modifications to the program were placed into the public domain, which meant that technically it didn't conform to section 3 of the Open Source definition. Newer versions don't have this requirement.
- ^ FreeOTFE version history
- ^ Security Token/Smartcard Support
- ^ Partition/Entire Disk Based Volumes
- ^ Additional Information for Windows Vista x64 and Windows 7 x64 Users
- ^ a b FreeOTFE v. FreeOTFE Explorer Comparison
See also
External links
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
