Description: The article presents an improved method for assessing the level of security of the network part of a special-purpose com-munication system from cyber threats based on the distribution identification algorithm and dynamic programming. One of the components of security systems for communication systems is a subsystem for assessing the level of security, which is designed to determine the effectiveness of the applied protection. The aim of the work is to develop a method for assessing the security of information processed in a communication system, based on managed multi-step decision-making processes, to increase the ef-fectiveness of information security management, taking into account the characteristics of the protection process. The amount of risk at each stage of the protection process is determined and the rule for the selection of protective equipment that minimizes the risk at all stages is defined. The process of assessing the protection of communication systems and the process of applying pro-tective equipment are implemented in stages. At each stage, a set of data on the security status of the system is obtained, which depends on the implemented security services, characterizes the security system and affects the choice of protective mechanisms. The vectors of the process of assessing security and the process of implementing protective equipment are determined that ensure minimization of the significance of risks at all stages of the functioning of the protection system. The essence of the method is to assess the level of security of communication systems using distributed identification of the parameters of cyberattacks, select measures to protect the system with a complete statistical description of the communication system and taking into account the strategies for the attacker to influence it based on dynamic programming. The recurrence relations and the rule of using protec-tive equipment are obtained, which determine the procedure for choosing the optimal protective mechanisms and are the basis for searching for optimal or close algorithms for using protective equipment with a priori uncertainty. They allow you to deter-mine the degree of security of communication systems based on the study of changes in its characteristics.
Keywords: cyber threats, special purpose systems, security, evaluation method, communication system.