Model of Information System Communication in Aggressive Cyberspace: Reliability, Functional Safety, Economics

The manuscript presents a mathematical apparatus for modeling the process of operation of the information system in the conditions of aggressive cyberspace, for which the corresponding parameter is provided. The highlight is that the simulation is carried out in the parametric space of reliability indicators, functional safety indicators, and economic indicators. The generalizing parameter in the mathematical apparatus is the coefficient of efficiency of operation of the studied system. It considers the accumulated parameter of efficiency of functioning of the studied system, the accompanying risk of its operation, and the number of resources invested in cybersecurity measures at its design stage. The connection of this coefficient with the probability of the information system transition to a non-functional state due to the realization of negative impact despite the resistance to cyber immune reaction is analytically described. The mathematical apparatus is developed to consider the errors of the first and second kind in identifying the negative impact on the information system. The search for the extreme value of the coefficient of the information system’s efficiency from the number of resources invested in its cybersecurity measures is described considering the characteristic parameters of cyberspace in which the studied system is operated. The functionality of the created mathematical apparatus is demonstrated in the example of a study of a real information system of the Situational Center of the Department of Information Technologies of the Vinnytsia City Council (Ukraine). The results obtained showed that the amount of funds invested in cybersecurity at the design stage of the studied information system is sufficient for its operation in cyberspace, typical for the region. At the same time, the growth dynamics of the accumulated operational efficiency characteristics outpaces the growth dynamics of the characteristics of the risk of studied information system operation. The simulation results coincide entirely with the empirical experience of the studied system operation, which allows us to recognize the created mathematical apparatus as adequate. The simulation showed that when the value of the probability of incorrect identification of the negative impact level intersects the value of ≈0.007, the studied system operational efficiency coefficient begins to decline rapidly. It indicates that the amount of resources invested in cybersecurity of the studied information system is exhausted.