In 1973 the U.S. National Bureau of Standards (NBS; now the National Institute of Standards and Technology) issued a public request for proposals for a cryptoalgorithm to be considered for a new cryptographic standard. No viable submissions were received. A second request was issued in 1974, and International Business Machines (IBM) submitted the patented Lucifer algorithm that had been devised by one of the company’s researchers, Horst Feistel, a few years earlier. The Lucifer algorithm was evaluated in secret consultations between the NBS and the National Security Agency (NSA). After some modifications to the internal functions and a shortening of ...(100 of 15098 words)