![FreeOTFE4PDA](https://upload.wikimedia.org/wikipedia/commons/f/f1/FreeOTFE4PDA.png)
FreeOTFE is a discontinued
open source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
computer program for
on-the-fly disk encryption (OTFE). On
Microsoft Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
, and
Windows Mobile
Windows Mobile is a discontinued family of mobile operating systems developed by Microsoft for smartphones and personal digital assistants.
Its origin dated back to Windows CE in 1996, though Windows Mobile itself first appeared in 2000 as Pock ...
(using FreeOTFE4PDA), it can create a
virtual drive
Virtual disk and virtual drive are software components that emulate an actual disk storage device.
Virtual disks and virtual drives are common components of virtual machines in hardware virtualization, but they are also widely used for various p ...
within a file or
partition
Partition may refer to:
Computing Hardware
* Disk partitioning, the division of a hard disk drive
* Memory partition, a subdivision of a computer's memory, usually for use by a single job
Software
* Partition (database), the division of a ...
, to which anything written is automatically encrypted before being stored on a computer's
hard
Hard may refer to:
* Hardness, resistance of physical materials to deformation or fracture
* Hard water, water with high mineral content
Arts and entertainment
* ''Hard'' (TV series), a French TV series
* Hard (band), a Hungarian hard rock supe ...
or
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
drive. It is similar in function to other disk encryption programs including
TrueCrypt
TrueCrypt is a discontinued source-available freeware utility used for on-the-fly encryption (OTFE). It can create a virtual encrypted disk within a file, or encrypt a partition or the whole storage device (pre-boot authentication).
On 28 May ...
and Microsoft's
BitLocker
BitLocker is a full volume encryption feature included with Microsoft Windows versions starting with Windows Vista. It is designed to protect data by providing encryption for entire volumes. By default, it uses the AES encryption algorithm in ...
.
The author, Sarah Dean, went absent as of 2011. The FreeOTFE website is unreachable as of June 2013 and the domain name is now registered by a
domain squatter. The original program can be downloaded fro
a mirror at Sourceforge In June 2014, a
fork
In cutlery or kitchenware, a fork (from la, furca 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods ei ...
of the project now named LibreCrypt appeared on
GitHub
GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continuous ...
.
Overview
''FreeOTFE'' was initially released by Sarah Dean in 2004, and was the first open source code disk encryption system that provided a modular architecture allowing 3rd parties to implement additional algorithms if needed. Older FreeOTFE licensing required that any modification to the program be placed in the
public domain
The public domain (PD) consists of all the creative work
A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...
. This does not conform technically to section 3 of the
Open Source definition
''The Open Source Definition'' is a document published by the Open Source Initiative, to determine whether a software license can be labeled with the open-source certification mark.
The definition was taken from the exact text of the Debian Free ...
. Newer program licensing omits this condition. The FreeOTFE license has not been approved by th
Open Source Initiativeand is not certified to be labeled with the open-source certification mark.
This software is compatible with Linux encrypted volumes (e.g.
LUKS,
cryptoloop Cryptoloop is a Linux kernel's disk encryption module that relies on the Crypto API, which is a cryptography framework introduced in version 2.5.45 of the Linux kernel mainline. Cryptoloop was first introduced in the 2.5.x kernel series; its func ...
,
dm-crypt
dm-crypt is a transparent block device encryption subsystem in Linux kernel versions 2.6 and later and in DragonFly BSD. It is part of the device mapper (dm) infrastructure, and uses cryptographic routines from the kernel's Crypto API. Unlike it ...
), 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
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...
and PDAs.
Optional
two-factor authentication
Multi-factor authentication (MFA; encompassing two-factor authentication, or 2FA, along with similar terms) is an electronic authentication method in which a user is granted access to a website or application only after successfully presenting ...
using
smart card
A smart card, chip card, or integrated circuit card (ICC or IC card) is a physical electronic authentication device, used to control access to a resource. It is typically a plastic credit card-sized card with an embedded integrated circuit (IC) c ...
s and/or
hardware security module
A hardware security module (HSM) is a physical computing device that safeguards and manages secrets (most importantly digital keys), performs encryption and decryption functions for digital signatures, strong authentication and other cryptograp ...
s (HSMs, also termed
security tokens
A security token is a peripheral device used to gain access to an electronically restricted resource. The token is used in addition to or in place of a password. It acts like an electronic key to access something. Examples of security tokens incl ...
) was introduced in v4.0, using the
PKCS#11 (Cryptoki) standard developed by
RSA Laboratories
RSA Security LLC, formerly RSA Security, Inc. and doing business as RSA, is an American computer and network security company with a focus on encryption and encryption standards. RSA was named after the initials of its co-founders, Ron Rivest, ...
.
''FreeOTFE'' also allows any number of "hidden volumes" to be created, giving
plausible deniability
Plausible deniability is the ability of people, typically senior officials in a formal or informal chain of command, to denial, deny knowledge of or responsibility for any damnable actions committed by members of their organizational hierarchy. Th ...
and
deniable encryption
In cryptography and steganography, plausibly deniable encryption describes encryption techniques where the existence of an encrypted file or message is deniable in the sense that an adversary cannot prove that the plaintext data exists.
The users ...
, and also has the option of encrypting full partitions or disks (but not the system partition).
Portable use
![FreeOTFEExplorer](https://upload.wikimedia.org/wikipedia/commons/8/86/FreeOTFEExplorer.png)
FreeOTFE can be used in "portable" (or "traveller") 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
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
without installation of the complete program to "mount" and access the encrypted data through a virtual disk.
The use of this mode requires installing
device drivers
In computing, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabling operating systems and ot ...
(at least temporarily) to create virtual disks, and as a consequence administrator rights are needed to start this traveller mode. As with most open source software that uses device drivers, the user must enable test signing when running Windows Vista x64 and Windows 7 x64 systems.
Additional Information for Windows Vista x64 and Windows 7 x64 Users
/ref>
Driverless operation
Packaged with FreeOTFE is another program called "FreeOTFE Explorer",
/ref> 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) public computers found in libraries or computer kiosks (interactive kiosk
An interactive kiosk is a computer terminal featuring specialized hardware and software that provides access to information and applications for communication, commerce, entertainment, or education.
By 2010, the largest bill pay kiosk network ...
s), where administrator rights are unavailable.
Unlike FreeOTFE, FreeOTFE Explorer does not provide on-the-fly encryption through a virtual drive. Instead it lets files be stored and extracted from encrypted disk images, in a similar manner as ZIP and RAR archives, by using a Windows Explorer
File Explorer, previously known as Windows Explorer, is a file manager application that is included with releases of the Microsoft Windows operating system from Windows 95 onwards. It provides a graphical user interface for accessing the file ...
like interface.
Algorithms implemented
Due to its architecture, FreeOTFE provides great flexibility to the user with its encryption options.
Ciphers
FreeOTFE implements several ciphers, including:
* AES
* Blowfish
Tetraodontidae is a family of primarily marine and estuarine fish of the order Tetraodontiformes. The family includes many familiar species variously called pufferfish, puffers, balloonfish, blowfish, blowies, bubblefish, globefish, swellfis ...
* CAST5 / CAST6
In cryptography, CAST-256 (or CAST6) is a symmetric-key block cipher published in June 1998. It was submitted as a candidate for the Advanced Encryption Standard (AES); however, it was not among the five AES finalists. It is an extension of an ...
* DES
Des is a masculine given name, mostly a short form (hypocorism) of Desmond. People named Des include:
People
* Des Buckingham, English football manager
* Des Corcoran, (1928–2004), Australian politician
* Des Dillon (disambiguation), sever ...
/ Triple DES
In cryptography, Triple DES (3DES or TDES), officially the Triple Data Encryption Algorithm (TDEA or Triple DEA), is a symmetric-key block cipher, which applies the DES cipher algorithm three times to each data block. The Data Encryption Standa ...
* MARS
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
* RC6
In cryptography, RC6 (Rivest cipher 6) is a symmetric key block cipher derived from RC5. It was designed by Ron Rivest, Matt Robshaw, Ray Sidney, and Yiqun Lisa Yin to meet the requirements of the Advanced Encryption Standard (AES) competition. ...
* Serpent
Serpent or The Serpent may refer to:
* Snake, a carnivorous reptile of the suborder Serpentes
Mythology and religion
* Sea serpent, a monstrous ocean creature
* Serpent (symbolism), the snake in religious rites and mythological contexts
* Serp ...
* Twofish
In cryptography, Twofish is a symmetric key block cipher with a block size of 128 bits and key sizes up to 256 bits. It was one of the five finalists of the Advanced Encryption Standard contest, but it was not selected for standardization. Twof ...
It includes all National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...
(NIST) Advanced Encryption Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001.
AES is a variant ...
(AES) finalists, and all ciphers can be used with multiple different keylengths.
Cipher modes
FreeOTFE originally offered encryption using cipher-block chaining
In cryptography, a block cipher mode of operation is an algorithm that uses a block cipher to provide information security such as confidentiality or authenticity.
A block cipher by itself is only suitable for the secure cryptographic transform ...
(CBC) with encrypted salt-sector initialization vector (ESSIV
Disk encryption is a special case of data rest protection when the storage medium is a sector-addressable device (e.g., a hard disk). This article presents cryptographic aspects of the problem. For an overview, see disk encryption. For discussion ...
), though from v3.00 introduced LRW LRW may refer to:
* Liskov-Rivest-Wagner, in cryptography
* Lifetime Real Women, US television channel
* Little Rock West High School, school in Arkansas
* Waco LRW, a military glider airplane
{{dab ...
and also the more secure XTS mode, which supersedes LRW in the IEEE P1619
Institute of Electrical and Electronics Engineers (IEEE) standardization project for encryption of stored data, but more generically refers to the Security in Storage Working Group (SISWG), which includes a family of standards for protection of st ...
standard for disk encryption.
Hashes
As with its cipher options, FreeOTFE offers many different hash algorithms:
* MD2
* MD4
The MD4 Message-Digest Algorithm is a cryptographic hash function developed by Ronald Rivest in 1990. The digest length is 128 bits. The algorithm has influenced later designs, such as the MD5, SHA-1 and RIPEMD algorithms. The initialism "MD" s ...
* MD5
* RIPEMD-128
* RIPEMD-160
* RIPEMD-224
* RIPEMD-320
* SHA-1
In cryptography, SHA-1 (Secure Hash Algorithm 1) is a cryptographically broken but still widely used hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest – typically rendered as 40 hexadecima ...
* SHA-224
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression ...
* SHA-256
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression ...
* SHA-384
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression ...
* SHA-512
SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård construction, from a one-way compression ...
* Tiger
The tiger (''Panthera tigris'') is the largest living cat species and a member of the genus '' Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on u ...
* Whirlpool
A whirlpool is a body of rotating water produced by opposing currents or a current running into an obstacle. Small whirlpools form when a bath or a sink is draining. More powerful ones formed in seas or oceans may be called maelstroms ( ). ''Vo ...
See also
* Disk encryption
Disk encryption is a technology which protects information by converting it into unreadable code that cannot be deciphered easily by unauthorized people. Disk encryption uses disk encryption software or hardware to encrypt every bit of data that g ...
* Disk encryption software
Disk encryption software is computer security software that protects the confidentiality of data stored on computer media (e.g., a hard disk, floppy disk, or USB device) by using disk encryption.
Compared to access controls commonly enforced by a ...
* On-the-fly encryption
Disk encryption is a technology which protects information by converting it into unreadable code that cannot be deciphered easily by unauthorized people. Disk encryption uses disk encryption software or hardware to encrypt every bit of data that g ...
* Comparison of disk encryption software
This is a technical feature comparison of different disk encryption software.
Background information
Operating systems
Features
* Hidden containers: Whether hidden containers (an encrypted container (A) within another encrypted container (B) ...
References
External links
*
*
{{Cryptographic software
Cryptographic software
Disk encryption
Free security software
Windows security software
Windows Mobile software
Portable software
Free software