Information and telecommunication resources of critical infrastructures: features of interval security analysis

The object of the research is a new methodological approach to solving the problem of interval analysis of the security of information and telecommunication resources of critical infrastructures. This approach is one of the variants of practising the methods of the class midvalues (interval calculations). The approach characteristics were analyzed to determine its validity and usefulness for assessing the security indicators of such complex technical systems over a time interval. There have been considered theoretical aspects of building the algorithms for calculating the class midvalues of security levels of information and telecommunication resources of critical infrastructures, factors of calculating the upper and lower class midvalues of security levels. A sequence of calculations and analytical expressions for calculations on the example of a specific security indicator are proposed. The approach offers taking into account the modern requirements of security management subsystems of complex technical systems, the requirements of officials (auditors, security administrators) related to the inertia of decision-making processes, with the duration of cycles of security control and security management of systems of this class. It allows one to obtain not point (instantaneous), but interval estimates of security indicators, while the analysis is carried out with a predetermined frequency and takes into account the uncertainty of the initial data – observed and controlled security indicators. At the same time, interval analysis does not have great mathematical and computational complexity, but it allows one to obtain interval estimates of resource security adequate to control and management tasks, saves computing resources and, ultimately, works to increase the reliability of security control of modern critical infrastructures.