Ant Colony Optimization for Cryptanalysis of Simplified-DES

Ant Colony Optimization is a search meta-heuristic inspired by the foraging behavior of real ant, having a very wide applicability. Especially, it can be applied to different combinatorial optimization problem. In this paper, we present a novel Ant Colony Optimization (ACO) based attack for cryptanalysis of Simplified Data Standard Encryption (S-DES). A known Plaintext attack is used to recover the secret key requiring only two Plaintext-Ciphertext pairs. Moreover, our approach allows us to break S-DES encryption system in a minimum search space when compared with other techniques. Experimental results prove that ACO can be considered as a convincing tool to attack the key used in S-DES.