Multiple anagramming is a general method for the cryptanalysis of transposition ciphers, and has a graph theoretic representation. Inspired by a partially mechanised approach used in World War II, we consider the possibility of a fully automated attack. Two heuristics based on measures of natural language are used one to recognise plaintext, and another to guide construction of the secret key. This is shown to be unworkable for cryptograms of a certain difficulty due to random variation in the constructive heuristic. A solver based on an ant colony optimisation (ACO) algorithm is then introduced, increasing the range of cryptograms that can be treated; the pheromone feedback provides a mechanism for the recognition heuristic to correct the noisy constructive heuristic.
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@inproceedings(SS-CEC-03, author = "Matthew D. Russell and John A. Clark and Susan Stepney", title = "Making the Most of Two Heuristics: Breaking Transposition Ciphers with Ants", pages = "2653-2658", crossref = "CEC-03" ) @proceedings(CEC-03, title = "CEC 2003: International Conference on Evolutionary Computation, Canberra, Australia, December 2003", booktitle = "CEC 2003: International Conference on Evolutionary Computation, Canberra, Australia, December 2003", publisher = "IEEE", year = 2003 )