A study of the problem of the security of information resources of intelligent computer networks for power supply management in railway power generation was conducted. The logical structure of an intelligent computer network is presented, reflecting the topological characteristics of the power supply distance, in the form of a graph. A conceptual approach to the organization of an optimal cyber security strategy is proposed. On the based of Pukhov's differential transformations, differential mathematical models are proposed for determining, in analytical form, the state probabilities of graph nodes. Based on the minimax principle, methods have been developed to determine the optimal cyber security strategy, which allows to achieve the specified security indicators. A criterion for ensuring information security is formulated, which allows determining the state of cyber security of each graph node and the probability of this node being in this state.