Breaking of Simplified Data Encryption Standard Using Binary Particle Swarm Optimization

Cryptanalysis of cipher text by using evolutionary algorithm has gained so much interest in last few years. This paper demonstrates the use of Binary Particle Swarm Optimization with bit change mutation operator for cryptanalysis of S-DES and then compared the results with Genetic Algorithm. An experimental result shows that Binary PSO performs better than the genetic algorithms for such type of problem. Here the cipher text attack is considered and several keys are generated in the iteration of the Binary Particle Swarm Optimization algorithm on the basis of their cost function value which depends upon letter frequency. 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.