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A Chaotic Key Expansion Algorithm Based on Genetic Algorithm

The key expansion algorithm is a critical factor that affects the encryption performance of block cipher. In view of the digital chaotic sequence, there are obvious degradation of the dynamic characteristics and the phenomenon of local periodicity, a chaotic key expansion algorithm based on genetic algorithm according to the genetic mechanism that survival of the fittest is proposed in this paper. Taking the digital chaotic sequence as the initial population, using the fitness function to evaluate the merits and demerits of the individual sequence, and performing the operations of the selection, crossover, and mutation, so that the generation and expansion of the key are realized through the generation-by-generation evolution. The simulation and test results show that the key expansion algorithm is safe and efficient, which is easy to implement and can better meet the encryption requirements of lightweight block cipher.