Serhii Pohasii

Prof. Dr. Serhii Pohasii

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
24 May 2021
Verified
Book
Open access
Serhii YevseievSerhii Yevseiev
Serhii Yevseiev
VPVolodymir Ponomarenko
Volodymir Ponomarenko
OLOleksandr Laptiev
Oleksandr Laptiev
OMOleksandr Milov
Oleksandr Milov
OKOlha Korol
Olha Korol
SFSerhii Florov
Serhii Florov
The development of the modern world community is closely related to advances in computing resources and cyberspace. The formation and expansion of the range of services is based on the achievements of mankind in the field of high technologies. However, the rapid growth of computing resources, the emergence of a full-scale quantum computer tightens the requirements for security systems not only for information and communication systems, but also for cyber-physical systems and technologies. The methodological foundations of building security systems for critical infrastructure facilities based on modeling the processes of behavior of antagonistic agents in security systems are discussed in the first chapter. The concept of information security in social networks, based on mathematical models of data protection, taking into account the influence of specific parameters of the social network, the effects on the network are proposed in second chapter. The nonlinear relationships of the parameters of the defense system, attacks, social networks, as well as the influence of individual characteristics of users and the nature of the relationships between them, takes into account. In the third section, practical aspects of the methodology for constructing post-quantum algorithms for asymmetric McEliece and Niederreiter cryptosystems on algebraic codes (elliptic and modified elliptic codes), their mathematical models and practical algorithms are considered. Hybrid crypto-code constructions of McEliece and Niederreiter on defective codes are proposed. They can significantly reduce the energy costs for implementation, while ensuring the required level of cryptographic strength of the system as a whole. The concept of security of corporate information and educational systems based on the construction of an adaptive information security system is proposed.

29 June 2023
Verified
Book
Open access
Serhii YevseievSerhii Yevseiev
Serhii Yevseiev
YKYuliia Khokhlachova
Yuliia Khokhlachova
SOSerhii Ostapov
Serhii Ostapov
OLOleksandr Laptiev
Oleksandr Laptiev
OKOlha Korol
Olha Korol
MTMaksym Tolkachov
Maksym Tolkachov
The development of technologies and computing resources has not only expanded the range of digital services in all spheres of human activity, but also determined the range of targeted cyber attacks. Targeted attacks are aimed at destroying not only the business structure, but also its individual components that determine critical business processes. The continuity of such business processes is a critical component of any company, organization or enterprise of any form of ownership, which has a critical impact on making a profit or organizing production processes. The proposed concept of determining the security level of critical business processes is based on the need to use multiloop information security systems. This makes it possible to ensure the continuity of critical business processes through a timely objective assessment of the level of security and the timely formation of preventive measures. This approach is based on the proposed rules for determining the reach of a given security level, based on assessments of the integrity, availability and confidentiality of information arrays, as well as computer equipment for different points of the organization's business processes. The issues of applying situational management methods to ensure the safe functioning of objects of socio-cyberphysical systems, logical and transformational rules that form the foundation for building a situational type cybersecurity management system are considered. One of the main tasks of systems of this type is described – the task of replenishing the description of the situation. The use of pseudophysical logics, various types of pseudophysical logics, the method of their construction and their interconnection are proposed. Particular attention is paid to causal pseudophysical logic, as the least developed for the purposes of ensuring cybersecurity. The formation of smart technologies, as a rule, uses the wireless standards of communication channels IEEE 802.11X, IEEE 802.15.4, IEEE 802.16, which use only authentication protocols and privacy mechanisms that are formed on the basis of symmetric algorithms. In the conditions of the post-quantum period (the appearance of a full-scale quantum computer), the stability of such algorithms is questioned. Such systems, as a rule, are formed on the basis of the synthesis of socio-cyber-physical systems and cloud technologies, which simplifies the implementation of Advanced Persistent Threat attacks, both on the internal loop of control systems and on the external one. The proposed creation of multi-circuit information protection systems allows for an objective assessment of the flow state of the system as a whole and the formation of preventive measures against cyber threats. In the thied chapter, models of probable threats and information protection in public networks are proposed. The most general model of the formal description of the protection system is the model of the security system with full overlap, in which a complete list of protection objects and threats to information is determined, and means of ensuring security are determined from the point of view of their effectiveness and contribution to ensuring the security of the entire telecommunications system. It is also shown that the combination of four models (M1, M2, M3, M4) in various variants provides wide opportunities for modeling various known types of threats and their implementation. However, in connection with the continuity of the process of developing new and improving existing methods and means of implementing threats, it is necessary to use such approaches to ensuring information protection that allow detecting and preventing threats of unknown types and carrying out dynamic correction of protection behavior, adapting it to specific application conditions. The M5 basic model is described, which enables continuous refinement of threat classes and response measures, and continuous training of the adaptive component of the CSI, which, in turn, detects and prevents threats of unknown types. The M6 basic model is introduced with the aim of obtaining higher security due to the presence of a special module of internal diagnostics that diagnoses the entire protection system, decides on the correction of the SHI behavior algorithm, and makes it possible to achieve SHI fault tolerance; a special module that diagnoses the communication channel with subsequent changes in the level of protection, allows to achieve the adaptability of the SHI. The fourth chapter is deal with the development of cryptographic primitives based on cellular automata. The definition of a cellular automaton is given and the elementary rules of intercellular interaction are described. A number of generators of pseudorandom binary sequences have been developed based on a combination of elementary rules of intercellular interaction, as well as cell interaction according to a rule of our own development. In the “cryptographic sponge” architecture, a cryptographic hashing function with a shuffling function based on cellular automata was developed and its statistical characteristics and avalanche effect were investigated. A block cipher in the SP-network architecture is constructed, in which cellular automata are used to deploy the key, and the encryption process is based on elementary procedures of replacement and permutation. Substitution blocks are used from the well-known AES cipher, a description of a stream cipher is given, where a personal computer keyboard and mouse are used as the initial entropy. Random data received from the specified devices is processed by a proprietary hashing function based on a "cryptographic sponge". All developed cryptographic functions and primitives demonstrated good statistical characteristics and avalanche properties. The fifth chapter proposes a methodology for analyzing the quality of the mechanism for validating the identified vulnerabilities of a corporate network,...

30 April 2022 in Eastern-European Journal of Enterprise Technologies
Verified
Journal Article
Open access
PDF file
SPSerhii Pohasii
Serhii Pohasii
Serhii YevseievSerhii Yevseiev
Serhii Yevseiev
OZOleksandr Zhuchenko
Oleksandr Zhuchenko
OMOleksandr Milov
Oleksandr Milov
VLVolodymyr Lysechko
Volodymyr Lysechko
VSVitalii Susukailo
Vitalii Susukailo
The results of developing post-quantum algorithms of McEliece and Niederreiter crypto-code constructs based on LDPC (Low-Density Parity-Check) codes are presented. With the rapid growth of computing capabilities of mobile technologies and the creation of wireless mesh and sensor networks, Internet of Things technologies, and smart technologies on their basis, information security is becoming an urgent problem. At the same time, there is a need to consider security in two circuits, internal (directly within the network infrastructure) and external (cloud technologies). In such conditions, it is necessary to integrate threats to both the internal and external security circuits. This allows you to take into account not only the hybridity and synergy of modern targeted threats, but also the level of significance (degree of secrecy) of information flows and information circulating in both the internal and external security circuits. The concept of building security based on two circuits is proposed. To ensure the security of wireless mobile channels, it is proposed to use McEliece and Niederreiter crypto-code constructs based on LDPC codes, which allows integration into the credibility technology of IEEE 802.15.4, IEEE 802.16 standards. This approach provides the required level of security services (confidentiality, integrity, authenticity) in a full-scale quantum computer. Practical security technologies based on the proposed crypto-code constructs, online IP telephony and the Smart Home system based on the use of an internal server are considered

31 October 2021 in Eastern-European Journal of Enterprise Technologies
Verified
Journal Article
Open access
PDF file
Serhii YevseievSerhii Yevseiev
Serhii Yevseiev
SPSerhii Pohasii
Serhii Pohasii
SMStanislav Milevskyi
Stanislav Milevskyi
OMOleksandr Milov
Oleksandr Milov
YMYevgen Melenti
Yevgen Melenti
OKOleg Kurchenko
Oleg Kurchenko
The paper presents the results of the development of a method for assessing the security of cyber-physical systems based on the Lotka–Volterra model. Security models of cyber-physical systems are proposed: “predator–prey” taking into account the computing capabilities and focus of targeted cyberattacks, “predator–prey” taking into account the possible competition of attackers in relation to the “prey”, “predator–prey” taking into account the relationships between “prey species” and “predator species”, “predator–prey” taking into account the relationship between “prey species” and “predator species”. Based on the proposed approach, the coefficients of the Lotka–Volterra model α=0.39, β=0.32, γ=0.29, φ=0.27 were obtained, which take into account the synergy and hybridity of modern threats, funding for the formation and improvement of the protection system, and also allow determining the financial and computing capabilities of the attacker based on the identified threats. The proposed method for assessing the security of cyber-physical systems is based on the developed threat classifier, allows assessing the current security level and provides recommendations regarding the allocation of limited protection resources based on an expert assessment of known threats. This approach allows offline dynamic simulation, which makes it possible to timely determine attackers' capabilities and form preventive protection measures based on threat analysis. In the simulation, actual bases for assessing real threats and incidents in cyber-physical systems can be used, which allows an expert assessment of their impact on both individual security services and security components (cyber security, information security and security of information). The presented simulation results do not contradict the graphical results of the classical Lotka–Volterra model, which indicates the adequacy of the proposed approach for assessing the security of cyber-physical systems

29 December 2021 in Eastern-European Journal of Enterprise Technologies
Verified
Journal Article
Open access
PDF file
Serhii YevseievSerhii Yevseiev
Serhii Yevseiev
YRYurii Ryabukha
Yurii Ryabukha
OMOleksandr Milov
Oleksandr Milov
SMStanislav Milevskyi
Stanislav Milevskyi
SPSerhii Pohasii
Serhii Pohasii
IPIgor Pasko
Igor Pasko
The development of the social aspect of the world community is closely related to the expansion of the range of digital services in cyberspace. A special place in which social networks occupy. The world's leading states are conducting information operations in this environment to achieve geopolitical goals. Such processes are reflected in real social and political life. This makes it possible to influence not only the social groups of society, but also to ensure manipulation in political "games" in the conduct of hybrid wars. The simultaneous interaction of social factors, influencing factors, the presence of communities in social networks forms a full-fledged socio-cyber-physical system capable of integrating real and virtual interactions to manage regional communities. The article proposes a method for predicting the assessment of social mutual influence between “formal” and “informal” leaders and regional societies. The proposed models make it possible to form not only a forecast of the influence of agents, but also the interaction of various agents, taking into account their formal and informal influences, the use of administrative resources, political moods of the regional society. This approach allows dynamic modeling based on impact and relationship analysis. The presented results of simulation modeling do not contradict the results of opinion polls and make it possible to form a set of measures that can be aimed at overcoming the negative impact on the regional society of both individual “leaders” and political parties. Analysis of the simulation results allows to increase both the political and social stability of the regional society, helps to prevent conflict moods and contradictions.

30 June 2022 in Eastern-European Journal of Enterprise Technologies
Verified
Journal Article
Open access
PDF file
Serhii YevseievSerhii Yevseiev
Serhii Yevseiev
VKVitaliy Katsalap
Vitaliy Katsalap
YMYurii Mikhieiev
Yurii Mikhieiev
VSVladyslava Savchuk
Vladyslava Savchuk
YPYurii Pribyliev
Yurii Pribyliev
IKIhor Korol
Ihor Korol
Research on the development of methods for identifying signs of hidden manipulation (destructive information and psychological impact) in text messages that are published on Internet sites and distributed among users of social networks is relevant. One of the main problems in the development of these methods is the difficulty of formalizing the process of identifying signs of manipulation in text messages of social network agents. To do this, based on morphological synthesis, it is necessary to determine relevant indicators for analyzing text messages and criteria for making a decision about the presence of signs of manipulation in text messages. Based on morphological synthesis, a method for determining manipulation indicators in text messages was developed, taking into account the achievements of modern technologies of intelligent content analysis of text messages, machine learning methods, fuzzy logic and computational linguistics, which made it possible to reasonably determine a group of indicators for evaluating text messages for signs of manipulation. The stages of the method include evaluating the text message at the level of perception by the indicator of text readability, at the phonetic level by the indicator of emotional impact on the subconscious, at the graphic level by the indicator of text marking intensity, and calculating the integral indicator for making a decision about the presence of manipulation in the text message. Based on the proposed method, specialized software was developed that provided 13 % greater accuracy in evaluating messages for manipulative impact compared to the known method of expert evaluations, which reduced the influence of the subjective factor on the evaluation result