METHOD AND APPARATUS FOR ENHANCING PERFORMANCE OF DATA ENCRYPTION STANDARD (DES) ENCRYPTION/DECRYPTION

摘要

A method and apparatus for increasing performance of Data Encryption Standard (DES) and Triple DES (3DES) cipher operation is provided. A critical path through a plurality of rounds in a multi-round cycle to perform a cipher operation is reduced by reducing the number of exclusive OR (XOR) operations in the critical path. An R state element is expanded to 48-bits and each round stage uses the 48-bit expanded R state element which results in a reduction of the number of XOR operations to one per round in the cipher operation plus one additional XOR operation per cipher operation. In addition logic organization is symmetric which further increases the overall performance of DES and 3DES.