Lucifer (cipher)

Lucifer was developed by IBM encryption method and the predecessor of DES. The name is inspired by the mythological figure of Lucifer.

Strictly speaking, there was a family of block ciphers, which were intended for civilian use. It was developed by Horst Feistel instrumental and his colleagues at IBM and is therefore also known as Feistelchiffre. In the 1970s, a Lucifer version was used in the electronic banking.

A known variant ( Feistel, 1973) uses a 128- bit key and works with blocks of 128 bits. It is a substitution permutation network and uses two 4 -bit S-boxes. The key selects each of the S-boxes.

A later version ( Sorkin, 1984) was a Feistel network in 16 rounds and also uses 128 -bit blocks and 128- bit keys.

IBM submitted the Feistel network variant as a candidate for the DES tender. After some modification (reduction to 56- bit key and the 64-bit blocks, but to differential cryptanalysis strengthened ), the method 1977 was assumed to be Data Encryption Standard.

The name " Lucifer" is a pun; Lucifer known in English a demon ( demon ), it was again the abbreviation of "demonstration", the name of a system on the Feistel worked. The operating system that he used did not allow filenames that length.