Mcrypt
Encyclopedia
mcrypt is a replacement for the popular UNIX
crypt
command.
crypt was a file encryption tool that used an algorithm
very close to the
World War II
enigma
cipher, which was broken. Mcrypt provides the same functionality but uses several modern algorithms such as AES
. Libmcrypt, Mcrypt's companion, is a library of code which contains the actual encryption functions and provides an easy method for use.
Examples of mcrypt usage in a linux command line environment:
mcrypt --list /* see available encryption algorithms */
mcrypt -a blowfish myfilename /* encrypts myfilename to myfilename.nc */
/* using blowfish encryption algorithm */
/* you are prompted 2x for passphrase */
mcrypt -d mytextfile.txt.nc /* decrypts mytextfile.txt.nc to mytextfile.txt */
mcrypt --help
It implements numerous cryptographic
algorithms, mostly block cipher
s and stream cipher
s, some of which falls under export restriction
s in the United States
. Algorithms include des
, blowfish
, arcfour, enigma
, ghost
, LOKI97
, RC2
, serpent
, threeway, twofish
, wake
, XTEA
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
crypt
Crypt (Unix)
In Unix computing, crypt is the name of both a utility program and a C programming function. Though both are used for encrypting data, they are otherwise essentially unrelated...
command.
crypt was a file encryption tool that used an algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...
very close to the
World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
enigma
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
cipher, which was broken. Mcrypt provides the same functionality but uses several modern algorithms such as AES
Advanced Encryption Standard
Advanced Encryption Standard is a specification for the encryption of electronic data. It has been adopted by the U.S. government and is now used worldwide. It supersedes DES...
. Libmcrypt, Mcrypt's companion, is a library of code which contains the actual encryption functions and provides an easy method for use.
Examples of mcrypt usage in a linux command line environment:
mcrypt --list /* see available encryption algorithms */
mcrypt -a blowfish myfilename /* encrypts myfilename to myfilename.nc */
/* using blowfish encryption algorithm */
/* you are prompted 2x for passphrase */
mcrypt -d mytextfile.txt.nc /* decrypts mytextfile.txt.nc to mytextfile.txt */
mcrypt --help
It implements numerous cryptographic
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...
algorithms, mostly block cipher
Block cipher
In cryptography, a block cipher is a symmetric key cipher operating on fixed-length groups of bits, called blocks, with an unvarying transformation. A block cipher encryption algorithm might take a 128-bit block of plaintext as input, and output a corresponding 128-bit block of ciphertext...
s and stream cipher
Stream cipher
In cryptography, a stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream . In a stream cipher the plaintext digits are encrypted one at a time, and the transformation of successive digits varies during the encryption...
s, some of which falls under export restriction
Export of cryptography
The export of cryptography in the United States is the transfer from the United States to another country of devices and technology related to cryptography....
s in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Algorithms include des
Data Encryption Standard
The Data Encryption Standard is a block cipher that uses shared secret encryption. It was selected by the National Bureau of Standards as an official Federal Information Processing Standard for the United States in 1976 and which has subsequently enjoyed widespread use internationally. It is...
, blowfish
Blowfish (cipher)
Blowfish is a keyed, symmetric block cipher, designed in 1993 by Bruce Schneier and included in a large number of cipher suites and encryption products. Blowfish provides a good encryption rate in software and no effective cryptanalysis of it has been found to date...
, arcfour, enigma
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
, ghost
Ghost
In traditional belief and fiction, a ghost is the soul or spirit of a deceased person or animal that can appear, in visible form or other manifestation, to the living. Descriptions of the apparition of ghosts vary widely from an invisible presence to translucent or barely visible wispy shapes, to...
, LOKI97
LOKI97
In cryptography, LOKI97 is a block cipher which was a candidate in the Advanced Encryption Standard competition. It is a member of the LOKI family of ciphers, earlier instances being LOKI89 and LOKI91...
, RC2
RC2
In cryptography, RC2 is a block cipher designed by Ron Rivest in 1987. "RC" stands for "Ron's Code" or "Rivest Cipher"; other ciphers designed by Rivest include RC4, RC5 and RC6....
, serpent
Serpent (cipher)
Serpent is a symmetric key block cipher which was a finalist in the Advanced Encryption Standard contest, where it came second to Rijndael. Serpent was designed by Ross Anderson, Eli Biham, and Lars Knudsen....
, threeway, twofish
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 was not selected for standardisation...
, wake
Wake
A wake is the region of recirculating flow immediately behind a moving or stationary solid body, caused by the flow of surrounding fluid around the body.-Fluid dynamics:...
, XTEA
XTEA
In cryptography, XTEA is a block cipher designed to correct weaknesses in TEA. The cipher's designers were David Wheeler and Roger Needham of the Cambridge Computer Laboratory, and the algorithm was presented in an unpublished technical report in 1997...