mcrypt is a replacement for the popular
Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...
crypt
A crypt (from Greek κρύπτη (kryptē) ''wikt:crypta#Latin, crypta'' "Burial vault (tomb), vault") is a stone chamber beneath the floor of a church or other building. It typically contains coffins, Sarcophagus, sarcophagi, or Relic, religiou ...
command. crypt was a file encryption tool that used an
algorithm
In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algo ...
very close to the
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
Enigma cipher. Mcrypt provides the same functionality but uses several modern algorithms such as
AES. Libmcrypt, Mcrypt's companion, is a library of code that contains the actual encryption functions and provides an easy method for use. The last update to libmcrypt was in 2007, despite years of unmerged patches. Maintained alternatives include
ccrypt,
libressl
LibreSSL is an open-source implementation of the Transport Layer Security (TLS) protocol. The implementation is named after Secure Sockets Layer (SSL), the deprecated predecessor of TLS, for which support was removed in release 2.3.0. The OpenBSD ...
, and others.
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 the Blowfish encryption algorithm.
# You are prompted two times for a passphrase.
mcrypt -d mytextfile.txt.nc # Decrypts mytextfile.txt.nc to mytextfile.txt.
mcrypt -V -d -a enigma -o scrypt --bare # Can en/decrypt files crypted with SunOS crypt.
mcrypt --help
It implements numerous
cryptographic
Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More gen ...
algorithms, mostly
block cipher
In cryptography, a block cipher is a deterministic algorithm that operates on fixed-length groups of bits, called ''blocks''. Block ciphers are the elementary building blocks of many cryptographic protocols. They are ubiquitous in the storage a ...
s and
stream cipher
stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream ( keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystrea ...
s, some of which fall under
export restrictions
Export restrictions, or a restriction on exportation, are limitations on the quantity of goods exported to a specific country or countries by a Government. Export restrictions could be aimed at achieving diverse policy objectives such as envir ...
in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
. Algorithms include
DES,
Blowfish,
ARCFOUR, Enigma,
GOST
GOST () refers to a set of international technical standards maintained by the Euro-Asian Council for Standardization, Metrology and Certification (EASC), a regional standards organization operating under the auspices of the Commonwealth of I ...
,
LOKI97,
RC2,
Serpent, Threeway,
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. Two ...
,
WAKE, and
XTEA.
See also
*
bcrypt
bcrypt is a password-hashing function designed by Niels Provos and David Mazières. It is based on the Blowfish (cipher), Blowfish cipher and presented at USENIX in 1999. Besides incorporating a salt (cryptography), salt to protect against rain ...
*
crypt (Unix)
In Unix computing, crypt or enigma is a utility program used for encryption. Due to the ease of breaking it, it is considered to be obsolete.
The program is usually used as a filter, and it has traditionally been implemented using a "rotor ...
*
ccrypt
*
scrypt
In cryptography, scrypt (pronounced "ess crypt") is a password-based key derivation function created by Colin Percival in March 2009, originally for the Tarsnap online backup service. The algorithm was specifically designed to make it costly t ...
References
External links
The original mcrypt homepageMCrypt homepageMCrypt development site
Cryptographic software
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