Editing Feistel cipher (section)

==History==
Many modern symmetric block ciphers are based on Feistel networks. Feistel networks were first seen commercially in IBM's [[Lucifer (cipher)|Lucifer]] cipher, designed by [[Horst Feistel]] and [[Don Coppersmith]] in 1973. Feistel networks gained respectability when the U.S. Federal Government adopted the [[Data Encryption Standard|DES]] (a cipher based on Lucifer, with changes made by the [[National Security Agency|NSA]]) in 1976. Like other components of the DES, the iterative nature of the Feistel construction makes implementing the cryptosystem in hardware easier (particularly on the hardware available at the time of DES's design).