monographic

As a monograph (also: monographic ; from Greek : μόνος ( monos ) = "sole" and γράφω ( grapho ) = "I write") or simply is in the cryptography an encryption (in particular, a substitution ) denotes where the plain text into individual characters is decomposed and one or more ciphertext characters are assigned to each individual plaintext character.

Depending on whether each plain text character is converted into a single, two or three ciphertext characters during encryption, a distinction is made between monopartite , bipartite and tripartite monographic substitutions.

Another distinguishing feature is whether only a single or several (many) different secret alphabets are used for encryption. In the first case, one speaks of a monoalphabetic substitution , otherwise of a polyalphabetic monographic substitution.

An example of a monographic monoalphabetic monopartite substitution is the shift cipher . The ENIGMA brought about a monographic polyalphabetic monopartite substitution.

In contrast to the monographic substitutions, there are the polygraphic substitutions, in which the plain text is not encoded by single characters but in groups of several (many) characters (e.g. bigraphic substitution ).

See also

• Cryptography terminology

literature

• Friedrich L. Bauer : Deciphered Secrets. Methods and maxims of cryptology. 3rd, revised and expanded edition. Springer, Berlin et al. 2000, ISBN 3-540-67931-6 , p. 46.