A Genetic Algorithm for Cryptanalysis with Application to DES-like Systems

Various cryptosystems use exhaustive techniques to search the key space. Such search techniques should be guided in order to be computationally adequate. Here, a Genetic Algorithm, GA, is proposed for the cryptanalysis of DES-like systems to find out the underlying key. The genetic algorithm approach is adopted, for obtaining the exact key by forming an initial population of keys that belong to the key subspace. In the proposed algorithms the premature convergence could be avoided by dynamic variation of control parameters that can affect the fitness function. In this paper a new method has been developed for the first time to break DES-like examples. These examples include both DES and FEAL with eight rounds. The performance of the propsed method, as such, is considerably faster than exhaustive search and differential cryptanalysis, DC. Therefore, it can be directly applied to a variety of DES-like systems instead of the current DC techniques.