A model for assessing the functional stability of information infrastructure elements for conditions of exposure to multiple computer attacks

Information is given about a new approach to the application of methods of the theory of semi-Markov processes to solve the applied problem of assessing the functional stability of elements that make up the information infrastructure, functioning under the influence of multiple computer attacks. The task of assessing functional stability is reduced to the task of finding the survivability function of the element under study and determining its extreme values. The relevance of the study is substantiated. The rationale is based on the assumption that quantitative methods of studying the stability of technical systems, which operate on the theory of reliability, cannot always be used to assess survivability. The concepts of «stability» and «computer attack» are being clarified. Verbal and formal statements of research tasks are formulated. The novelty of the results obtained lies in the application of well-known methods to solve a practically significant problem in a new formulation, taking into account the limitations on the resource allocated to maintain the survivability of the element under study, provided that arbitrary distribution laws are adopted for the random times of the implementation of computer attacks and the recovery times of the functional element. Recommendations on the formation of initial data, the content of the enlarged stages of modeling and a test case to demonstrate the performance of the model are given. The results of the test simulation are presented in the form of graphs of the survivability function. The resulting application can be used in practice to construct a survivability function when implementing up to three computer attacks, as well as a tool for evaluating the reliability of analogous statistical models. The limitation is explained by a progressive increase in the dimension of the analytical model and a decrease in the possibility of its meaningful interpretation.