Kozubtsova L. Improvement of methods for monitoring the cyber stability of a special-purpose information system

Dissertation for obtaining the degree of the Candidate of Technical Sciences in the specialty 05.13.05 – "Computer systems and components". – Open International University of Human Development "Ukraine"; Kyiv, 2020. In this dissertation it is solved a relevant scientific task - improvement of methods for monitoring the cyber stability of a special-purpose information system, calculating cyber resilience that became the basis for a method of monitoring cyber resilience of a special-purpose information system. In the dissertation study it is revealed a contradiction between the objective need of special users in a special-purpose information system adapted to operate in cyberspace; constant vulnerability and insecurity of a special-purpose information system from zero-day threats that appears in unpredictability of cyber resilience; the lack of adequate methods of monitoring cyber resilience of a special-purpose information system. Identified contradictions and practical importance of monitoring of cyber resilience of a special-purpose information system, networks and components caused the necessity in control methods, determination of parameters of computer systems and networks, their devices and components led to the solution of a scientific problem and choice of research topic – “Improvement of methods for monitoring the cyber stability of a special-purpose information system", which corresponds to the scientific specialty 05.13.05 - "Computer systems and components". The most important scientific results obtained in the dissertation are: 1. The method of monitoring the cyber stability of a special-purpose information system has been improved. The difference between this method and existing ones is that the method is based on procedures for decomposing an information system into components based on the criterion of vulnerability to destructive information impacts. The stages of planned / unplanned passive and active monitoring of cyber security and analytical calculations of cyber security risk are applied. The method allows to calculate the cyber stability of system components and to predict the possible risk of cyber security in order to minimize losses of user information. 2. The method of calculating the cyber stability indicators of a special-purpose information system has been improved. The difference between this method and the existing ones is that the method is based on analytical calculations of cyber stability of decomposed components of the information system and the system as a whole, the initial data of which is extracted as a result of using methods of passive and active monitoring of the information system. This method allows you to calculate the system's cyber stability indicators for a certain time period. 3. The method of combined monitoring of cyber security of a special-purpose information system has been improved. The difference between this method and the existing ones is that it is based on a combination of passive and active monitoring of cyber security of the information system and analytical expressions that take into account the coefficients of functional performance of system components that are sensitive to destructive information impacts. The method allows you to get numerical values of cyber security of the information system at a certain time in the absence and presence of destructive influences. The set of scientific provisions formulated and justified in the dissertation work is a solution to the current scientific problem of improvement of methods for combined monitoring of cyber security, calculating indicators of cyber stability, which are the basis of the method for monitoring the cyber stability of a special-purpose information system. Thus, the set scientific tasks have been solved in full, the research goal has been achieved, namely, to increase the cyber stability of the special-purpose information system in cybernetic space in the conditions of accidental actions of external destructive information influences. Due to the high dynamics of the subject area expansion, it is advisable to direct the research to expand the monitoring of parameters that affect the increase of cybersecurity of special-purpose information system components. Keywords: method, monitoring, cyber stability, cyber reliability, cyber survivability, cybersecurity, special-purpose information system, cyberspace.