In today's information-oriented world, ensuring secure and efficient communication is of paramount importance. Traditionally, the security of symmetric cryptosystems relies on the complexity of mathematical calculations. However, modern approaches have begun to explore alternative methods that combine mathematical calculations with innovative methods. In this paper, we present a symmetric cryptosystem built using genetic algorithms and a pseudorandom number generator. The article provides a description of the cryptosystem construction algorithm, its implementation in the Python programming language, and an analysis of the cryptosystem.