What is cipher?

  • (noun): A message written in a secret code.
    Synonyms: cypher
    See also — Additional definitions below


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 is encipherment. To encipher or encode is to convert information from plain text into code or cipher. In non-technical usage, a "cipher" is the same thing as a "code"; however, the concepts are distinct in cryptography. In classical cryptography, ciphers were distinguished from codes. Codes operated by substituting according to a large codebook which linked a random string of characters or numbers to a word or phrase. For example, "UQJHSE" could be the code for "Proceed to the following coordinates". When using a cipher the original information is known as plaintext, and the encrypted form as ciphertext. The ciphertext message contains all the information of the plaintext message, but is not in a format readable by a human or computer without the proper mechanism to decrypt it.

Read more about Cipher.

Some articles on cipher:

Cipher - Key Size and Vulnerability
... lacking any other information to help break a cipher), three factors above all, count Mathematical advances that allow new attacks or weaknesses to be discovered and ... multiple reports to suggest that a symmetric cipher with 128 bits, an asymmetric cipher with 3072 bit keys, and an elliptic curve cipher with 512 bits, all have similar difficulty ... that any theoretically unbreakable cipher must have keys which are at least as long as the plaintext, and used only once one-time pad ...
Cipher (newuniversal) - Fictional Character Biography - Project Spitfire
... The original suit was created by Anthony Stark in 1959 who became Cipher in the "The Fireworks" event in 1955, and is an alternate version of Tony Stark (Iron Man) from ... Swann herself was transformed by the White Event when the Cipher glyph bonded with her, acquiring similar superhuman abilities as Anthony Stark (the glyph appears as a tattoo on the back of her neck) ... The superhuman abilities granted by the Cipher glyph allowed her to swiftly complete the H.E.X ...
Lists Of British Inventions - Cryptography
... Playfair cipher - Charles Wheatstone Bacon's cipher - Sir Francis Bacon RSA cipher - Clifford Cocks developed the RSA algorithm at GCHQ, approximately three years before it was independently developed by Rivest ...
Cipher (comics) - Fictional Character Biography
... of Young X-Men #8, however her codename is spelled "Cipher" rather than "Cypher" (as it is spelled in earlier mentions) ... Cyclops reveals that Cipher was first discovered during events depicted in New X-Men vol ... Cyclops chose to keep Alisa's presence a secret per her request, giving her the codename "Cipher," an act made easier by Alisa's mutant ability to become completely undetectable either psychically or physically ...

More definitions of "cipher":

  • (noun): A mathematical element that when added to another number yields the same number.
    Synonyms: zero, 0, nought, cypher

Famous quotes containing the word cipher:

    The eye is the first circle; the horizon which it forms is the second; and throughout nature this primary figure is repeated without end. It is the highest emblem in the cipher of the world.
    Ralph Waldo Emerson (1803–1882)

    It is not an arbitrary “decree of God,” but in the nature of man, that a veil shuts down on the facts of to-morrow; for the soul will not have us read any other cipher than that of cause and effect. By this veil, which curtains events, it instructs the children of men to live in to-day.
    Ralph Waldo Emerson (1803–1882)