Horst Feistel
More info
- Born
- Died
- Known for
- The Feistel network, Lucifer
- Nationality
- German-American
The German-American at IBM who gave the block cipher its structure — and thereby DES, and thereby twenty years of banking encryption.
Born in Berlin, he emigrated to the United States in 1934. During the Second World War he was placed under travel restrictions as a German national and did not receive US citizenship until 1944. After the war he worked on identification systems for the Air Force, joining IBM in 1968 where he was given a cryptography group to lead.
There he developed the Lucifer cipher and the round structure that bears his name: the block is split into halves, and the round function need not be invertible. Lucifer became the basis for DES, a federal standard in 1977. Feistel worked in a field where the NSA actively discouraged open publication, and his 1973 Scientific American article was one of the first accessible descriptions of modern cryptography.