New Approach for Modifying DES Algorithm by Using Multiple Keys Depend on Heuristic Search Algorithm

Abstract

In this paper, artificial search algorithm(breath algorithm ) are used to design a symmetric key cryptography system based on DES algorithm,the LFSRs and breath algorithm are applied to generate a pseudo-random numbers sequence (PNS) which is used during the encryption process. The quality of PNSs highly depends on the set of LFSRs rule by selected the polynomial equation cells . This paper introduces a new method to enhance the performance of the Data Encryption Standard (DES) Algorithm. This is done by building a new structure for the 16 rounds in the original algorithm. This structure makes use of multiple secrete keys and the length of key is256-bits to process one block 256-bits of plain text.