Various cryptosystems exploit exhaustive techniques to search, missing-the-mark, 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. The premature convergence (local minimum) 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 with eight rounds. Its performance is considerably faster than exhaustive search and differential cryptanalysis, DC. The new method can be applied to a variety of DES-like systems instead of the available DC techniques.
Hasan Mohammed Hasan Husein, Bayoumi I. Bayoumi, F