Browsing by Author "Boyarchuk, A."

Now showing 1 - 12 of 12
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    Availability assessment of information and control systems with online software update and verification
    (Springer Verlag, 2014) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.
    The paper is devoted to the analysis of the verification objectives and features for information and control systems (ICS) software at the different stages of life cycle, in particular, on development and operation stages for space ICS software. Theoretic-set description of objectives, verified functions considering their criticality for space systems software and scenarios of online verification are proposed. Availability Markov chains based models are developed for different scenarios of space systems software online verification. Multi-fragment Markov models of ICS software for a serviced spacecraft is researched taking into account updating and removal of detected faults.
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    Basic Models for Dependable Web-Services: Technique for Development and Research
    (Oficyna Wydawnicza Politechnki Wroclawskiej, 2010) Ponochovnyi, Y. L.; Boyarchuk, A.; Kharchenko, V.; Odaruschenko, Oleg
    Objective of the chapter is development of the basic models and technique for modeling and dependability assessment of Web-services for different variants of SOA. The structure of the chapter is the following. The set of the basic models for the different cases of Web-services (Web-services with and without availability losses, composite Web-services) and aggregated models which combine the dif-ferent cases is proposed in the second and third sections accordingly. The forth section is dedicated to development of the model for Web-service with availabil-ity loss. Some results of implementation of the proposed technique and directions of further research are discussed in the last section.
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    Monte-Carlo simulation and availability assessment of the smart building automation systems considering component failures and attacks on vulnerabilities
    (Springer Verlag, 2019) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Brezhnev, E.; Andrashov, A.; Поночовний, Юрій Леонідович
    The information and control system of smart building is considered as a set of subsystems including a building automation system (BAS) which has three-level structure (automation/control, communication, data base, cloud/management). BAS security and availability during its life cycle are assessed using the Markov models and Monte-Carlo simulation. Markov model is used to calculate BAS availability considering the possibility of recovery and different kinds of the faults. The Monte-Carlo simulation is applied to investigate any flow of intrusions into the BAS by analyzing system availability of a fault/vulnerability to occur during time depending on failure rate of its subsystems. The results of analytical and simulation modeling are compared to assure trustworthiness of availability assessment taking into account attacks on vulnerabilities
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    Multi-Fragmental Markov Models of Information and Control Systems Safety Considering Elimination of Hardware-Software Faults
    (2019) Ponochovnyi, Y. L.; Kharchenko, V.; Boyarchuk, A.; Andrashov, A.; Поночовний, Юрій Леонідович
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    Multi-Fragmental Markov Models of Information and Control Systems Safety Considering Elimination of Hardware-Software Faults
    (2019) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Andrashov, A.; Поночовний, Юрій Леонідович
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    Multi-fragmental Markov’s Models for Safety Assessment of NPP I&C System Considering Migration of Hidden Failures
    (2019) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Andrashov, A.; Rudenko, I.; Поночовний, Юрій Леонідович
    The information and control systems of Nuclear Power Plant and other safety critical systems are considered as a set of three independent hard-ware channels including online testing system. Nuclear Power Plant information and control systems design on programmable platforms Vemodel of the life cycle. Safety and availa assessed using Markov and multfragmental models. The mult-fragmental model MICS32 contains an absorbing state in case of hidden faults and allows luating risks of “hidden” unavailability. The MICS42 model “migration” of states with undetected failures into states with detected faults. These models describe the functioning of the system and the complete elimi-nation of software faults. Results of multi-fragmental modeling are compared to evaluate proof test period taking into account requirements for SIL3 level and limiting values of hidden fault probabilities. Multi-fragment models are included in the assessing method of implementation safety requirements of ICS on pro-grammable platforms. The information technology of decision support in assessing and managing the implementation of the requirements for ICS safety is also considered.
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    Resilience assurance for software-based space systems with online patching: Two cases
    (Springer Verlag, 2016) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Brezhnev, E.; Поночовний, Юрій Леонідович
    The paper discusses the problems of resilient software engineering for unmanned software-based space systems. Resilience is achieved by online patching of software upon emergence of defects providing a stable link to the ground control center. Based on the specifics of satellite orbits it offers two case models: a multifragment one—for systems with a continuous link from geostationary orbits; a multiphase one—for recurrent link from elliptic orbits. The results of the modeling offer the possibility to plan the values of the software initial failure rate and the period of preventive tests that would ensure required reliability and availability.
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    Scenario-based Markovian modeling of web-system availability considering attacks on vulnerabilities
    (CEUR-WS, 2015) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Gorbenko, A.
    In the paper we simulate web-system availability taking into account security aspects and different maintenance scenarios. As a case study we have developed two Markov's models. These models simulate availability of a multi-tier web-system considering attacks on DNS vulnerabilities in additional to sys-tem failures due to hardware/software (HW/SW) faults. Proposed Markov's model use attacks rate and criticality as initial simulation parameters. In the paper we demonstrate how to estimate these parameters using open vulnerability databases (e.g. National Vulnerability Database). We also define different vulnerability elimination (VE) scenarios and examine how they affect system availability
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    Secure hybrid clouds: Analysis of configurations energy efficiency
    (Springer Verlag, 2015) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Gorbenko, A.; Поночовний, Юрій Леонідович
    The paper examines energy efficiency of running computational tasks in the hybrid clouds considering data privacy and security aspects. As a case study we examine CPU demanding high-tech methods of radiation therapy of cancer. We introduce mathematical models comparing energy efficiency of running our case study application in the public cloud, private data center and on a personal computer. These models employ Markovian chains and queuing theory together to estimate energy and performance attributes of different configurations of computational environment. Finally, a concept of a Hybrid Cloud which effectively distributes computational tasks among the public and secure private clouds depending on their security requirements is proposed in the paper
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    Security and availability models for smart building automation systems
    (Research Institute of Intelligent Computer Systems, 2017) Kharchenko, V.; Ponochovnyi, Y. L.; Boyarchuk, A.; Qahtan, A.-S.M.; Поночовний, Юрій Леонідович
    This article presents the information on control system of smart building, which is considered as a set of subsystems including a building automation system. The paper considers the three-level architecture of the building automation system components, including FPGA, communication and management levels. It is determined that the causes of failures and inaccessibility of the BAS architecture component can be both internal system and external factors, among which software defects and vulnerabilities are identified. BAS security and availability during its life cycle are assessed using the Fault-, Attack- and Availability-Tree and Markov models. Markov model is used to develop a number of strategies which help to recover system and to eliminate all the possible threats during systems life time. The models of BAS architecture with software defects and attacked vulnerabilities with general reliability (defect) and security (vulnerability) maintenance are analyzed in detail. The recommendations on the choice of strategies and service parameters are given.
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    The Availability Models of Two-Zone Physical Security System Considering Cyber Attacks
    (2020) Kharchenko, V.; Ponochovnyi, Y. L.; Waleed AK. A.; Boyarchuk, A.; Brezhniev, Y.; Поночовний, Юрій Леонідович
    Relevance of the paper is confirmed by the need to protect the security systems themselves, not only from physical damage, but also from ceyber attacks hy intruders. The paper explores the Markov model of the two-zone cyber-physical security system. Evaluation of the functioning of the multi zone system was carried out taking into account two degrees of degradation (operative condition - the failure state ofall zones). The state space of the model (or one fragment) has a dimension of 9 states. In the proposed model, hardware failures caused by vandal attacks on objects of the first zone and software failures due to cyber attacks on the functions ofthe second zone are considered. The simulation results illustrate different transition intervals of availability indicators of various levels of degradation to a stationary state. For different degrees of degradation, the minimum value of the availabilty function, the time interval ofthe transition of the availability function to the stationary mode, and the Value of the availability function in the stationary mode are determined. When eliminating software defects and vulnerabilities, the increase in the availability function is 0.234 for a zero level of system degradation.
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    Web systems availability assessment considering attacks on service configuration vulnerabilities
    (Springer Verlag, 2014) Kharchenko, V.; Abdul-Hadi, A.M.; Boyarchuk, A.; Ponochovnyi, Y. L.
    The paper examines the issues of web systems assessment availability. It is defined that unavailability of web services may be caused by internal and external factors in particular server side vulnerability attacks. Three Markov’s models of web system availability are developed; these models consider influence of software defects and vulnerability attacks for DNS, DHCP and Route services. Elimination of configuration vulnerabilities during system operation is considered. Conclusions about the impact of the probability of detection and elimination of vulnerabilities and the recovery rate on the web systems availability function are proposed.