Data Encryption Standard (DES)

Background TheData Encryption Standard (DES) [] has been around for more than  years. During this time, the standard was revised three times: as FIPS-- in , as FIPS-- in , and as FIPS-- in . DES was an outcome of a call for primitives in , which did not result in many serious candidates except for a predecessor of DES, Lucifer [, ] designed by IBM around . It took another year for a joint IBM–NSA effort to turn Lucifer intoDES.The structure of Lucifer was significantly altered: Since the design rationale was never made public and the secret key size was reduced from -bit to -bits, this initially resulted in controversy, and some distrust among the public. After some delay, FIPS- was published by NBS (National Bureau of Standards) – nowNIST (National Institute of Standards and Technology) – on January ,  [] (see [] for a discussion of the standardization process). However, in spite of all the controversy it is hard to underestimate the role of DES []. DES was one of the first commercially developed (as opposed to government developed) ciphers whose structure was fully published. This effectively created a community of researchers who could analyze it and propose their own designs. This led to a wave of public interest in cryptography, from which much of the cryptography as we know it today was born.