Cipher
In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term...
Cipher - Wikipedia
Dutch police 'read' Blackberry emails
A police forensics unit has claimed that it can decrypt messages on locked-down Blackberry handsets.
600 year old mystery manuscript decoded by University of Bedfordshire professor - beds.ac.uk
A professor from the University of Bedfordshire has followed in the footsteps of Indiana Jones by cracking the code of a 600 year old manuscript, deemed as ‘the most mysterious’ document in the world....
History of cryptography
Cryptography, the use of codes and ciphers to protect secrets, began thousands of years ago. Until recent decades, it has been the story of what might be called classic cryptography — that is, of met...
History of cryptography - Wikipedia
Block ciphers
In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called blocks, with an unvarying transformation that is specified by a symmetric key. Block ciphe...
Block ciphers - Wikipedia
Classical cipher
A cipher is a means of concealing a message, where letters of the message are substituted or transposed for other letters, letter pairs, and sometimes for many letters. In cryptography, a classical ci...
Stream cipher
A 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 wi...
Stream cipher - Wikipedia
Reciprocal cipher
A reciprocal cipher means, just as one enters the plaintext into the cryptography system to get the ciphertext, one could enter the ciphertext into the same place in the system to get the plaintext. S...
Solitaire (cipher)
The Solitaire cryptographic algorithm was designed by Bruce Schneier to allow field agents to communicate securely without having to rely on electronics or having to carry incriminating tools, at the ...
Trithemius cipher
In cryptography, the tabula recta (from Latin tabula rēcta) is a square table of alphabets, each row of which is made by shifting the previous one to the left. The term was invented by the German auth...
Trithemius cipher - Wikipedia
Bletchley Park
Bletchley Park, in Milton Keynes, Buckinghamshire, was the central site of the United Kingdom's Government Code and Cypher School (GC&CS), which during the Second World War regularly penetrated th...
Bletchley Park - Wikipedia
Rotor machine
In cryptography, a rotor machine is an electro-mechanical stream cipher device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state-of-the-art for a prominen...
Rotor machine - Wikipedia
Undeciphered writing systems
Many undeciphered writing systems date from several thousand years BC, though some more modern examples do exist. The term "writing systems" is used here loosely to refer to groups of glyphs which app...
Venona project
The Venona project was a counter-intelligence program initiated by the United States Army Signal Intelligence Service (a forerunner of the National Security Agency) that lasted from 1943 to 1980. The ...
Venona project - Wikipedia
List of ciphertexts
Some famous ciphertexts (or cryptograms) are:
40-bit encryption
40-bit encryption refers to a key size of forty bits, or five bytes, for symmetric encryption; this represents a relatively low level of security. A forty bit length corresponds to a total of 2 possib...
AACS encryption key controversy
A controversy surrounding the AACS cryptographic key arose in April 2007 when the Motion Picture Association of America and the Advanced Access Content System Licensing Administrator, LLC (AACS LA) be...
AACS encryption key controversy - Wikipedia
The Alphabet Cipher
Lewis Carroll published The Alphabet-Cipher in 1868, possibly in a children's magazine. It describes what is known as a Vigenère cipher, a well-known scheme in cryptography. While Carroll calls this ...
The Alphabet Cipher - Wikipedia
Babington Plot
The Babington Plot was a plot in 1586 to assassinate Queen Elizabeth, a Protestant, and put the rescued Mary, Queen of Scots, her Roman Catholic cousin, on the English throne. It led to the execution ...
Babington Plot - Wikipedia
Beale ciphers
The Beale ciphers, also referred to as the Beale Papers, are a set of three ciphertexts, one of which allegedly states the location of a buried treasure of gold, silver and jewels estimated to be wort...
Beale ciphers - Wikipedia
Code talker
Code talkers are people in the 20th century who used obscure languages as a means of secret communication during wartime. The term is now usually associated with the United States soldiers during the ...
Code talker - Wikipedia
Code-talker paradox
A code-talker paradox is a situation in which a language prevents communication. As an issue in linguistics, the paradox raises questions about the fundamental nature of languages. As such, the para...
Content Scramble System
Content Scramble System (CSS) is a digital rights management (DRM) and encryption system employed on almost all commercially produced DVD-Video discs. CSS utilizes a proprietary 40-bit stream cipher a...
Cryptanalysis of the Enigma
Cryptanalysis of the Enigma enabled the western Allies in World War II to read substantial amounts of secret Morse-coded radio communications of the Axis powers that had been enciphered using Enigma m...
Cryptanalysis of the Enigma - Wikipedia
Cryptogram
A cryptogram is a type of puzzle that consists of a short piece of encrypted text. Generally the cipher used to encrypt the text is simple enough that cryptogram can be solved by hand. Frequently used...
Cryptogram - Wikipedia
Cryptography in Japan
The cipher system that Uesugi used is basically a simple substitution usually known as a Polybius square or “checkerboard.” The i-ro-ha alphabet contains forty-eight letters, so a seven-by-seven squar...