Generalized model of actions by an attacker when manipulating messages containing precise time signals

This article gives the place and role of the common time system in the telecommunications system, gives an overview of the process of functioning of the common time system, indicating the main means of transmitting accurate time signals. Based on the analysis of the process of functioning of the common time system, the main risks of failures in technological and automated systems in case of violation of the accuracy of the transmission of common time signals are identified. As a result of the analysis of emerging risks, attention is focused on the main types of threats to the single time system when attacks are carried out by organized malefactors. A special place among the threats is occupied by the manipulation of messages containing precise time signals. To analyze this threat, a semi-Markov model of an attacker's actions when manipulating messages containing precise time signals is formed. The main stages of the process of carrying out the attack are singled out. Using the method of minors, the main stationary characteristics of the attack process are calculated, such as the probability of finding the attack process at various stages of its implementation, as well as the average time of the attack duration and the average recovery time of the unified time system from the consequences of the attack. This information also serves as the basis for determining the coefficient of correct operation of the unified time system. The results obtained can be reflected in the formation of strategies for protecting the unified time system from attacks by organized intruders.