Abstract

Cryptanalysis of ciphertext by using evolutionary algorithm has gained so much interest in recent years. In this paper we have used a Genetic algorithm with improved crossover operator (Ring Crossover) for cryptanalysis of SDES. There so many attacks in cryptography. The cipher text attack only is considered here and several keys are generated in the different run of the genetic algorithm on the basis of their cost function value which depends upon frequency of the letters. The results on the S-DES indicate that, this is a promising method and can be adopted to handle other complex block ciphers like DES, AES.