The Data Encryption Standard (DES) [31] has been around for more than 25 years. During this time the standard was revised three times: as FIPS-46-1 in 1988, as FIPS-46-2 in 1993 and as FIPS-46-3 in 1999. DES was an outcome of a call for primitives in 1974, which did not result in many serious candidates except for a predecessor of DES, Lucifer [15, 36] designed by IBM around 1971. It took another year for a joint IBM–NSA effort to turn Lucifer into DES. The structure of Lucifer was significantly altered: since the design rationale was never made public and the secret key size was reduced from 128-bit to 56-bits, this initially resulted in controversy, and some distrust among the public. After some delay, FIPS-46 was published by NBS (National Bureau of Standards)—now NIST (National Institute of Standards and Technology)—on January 15, 1977 [31] (see [35] for a discussion of the standardization process).
However, in spite of all the controversy it is hard to underestimate the role of.
