Des Algorithm Architectures and Implementations

The DES algorithm [35] is the best known and most widely used encryption algorithm. IBM developed DES in the mid 1970s as a modification of an earlier system known as Lucifer. In 1976, DES was adopted by the National Bureau of Standards (NBS), now the NIST, as a federal standard and authorised for use on all classified government communications. It has been the standard algorithm for banking and other applications since 1977. Although the private-key algorithm has recently been replaced by the Advanced Encryption Standard (AES) algorithm, DES will still remain in the public domain for a number of years because of legacy requirements. It provides a basis of comparison for new algorithms and it is also used in IPSec protocols, ATM cell encryption, the Secure Socket Layer (SSL) protocol and in Triple-DES, adopted to improve DES in the X9.17 and ISO 8732 standards [36, 37].