An Evolutionary Approach for the Playfair Cipher Cryptanalysis

In this paper we describe the Playfair substitution cipher and we propose an evolutionary algorithm for Playfair’s cryptanalysis. The structural properties of the cipher and its enciphering rules determine the suitability of an evolutionary, genetic-like approach for the cipher’s cryptanalysis. Classical cryptographic ciphers like Playfair are no longer used in practice, but evolutionary approaches as the one we propose can be used for modern cryptographic ciphers/algorithms analysis in order to study cryptographic operations, components or modules and for avoiding time consuming approaches like exhaustive enumerations of search spaces (e.g. keys spaces).