Attacks on the Transposition Ciphers Using Optimization Heuristics

TLDR: Three optimization heuristics are presented which can be utilized in attacks on the transposition cipher, which are simulated annealing, genetic algorithm and tabu search and it is shown that each provides effective automated techniques for the cryptanalysis of the ciphertext.

Abstract: In this paper three optimization heuristics are presented which can be utilized in attacks on the transposition cipher. These heuristics are simulated annealing, genetic algorithm and tabu search. We will show that each of these heuristics provides effective automated techniques for the cryptanalysis of the ciphertext. The property which make this cipher vulnerable, is that it is not sophisticated enough to hide the inherent properties or statistics of the language of the plaintext. In Table 1 is shown the key and the encryption process of the previously described transposition cipher. It can be noticed that the random string "X" was appended to the end of the message to enforce a message length, which is a multiple of the block size. It is also clear that the decryption can be achieved by following the same process as encryption using the "inverse" of the encryption permutation. In this case