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Copyright of Informatics & Mathematical Methods in Simulation / Informatika ta Matematičnì Metodi v Modelûvannì is the property of Odessa Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The problem of solving the task of discrete optimization is not completely solved. Lack of publications, scientific developments, algorithms and software products do not give the ability to transfer the mathematical apparatus of solving discrete optimization problems to the class P of computational complexity. All analytical and combinatorial algorithms for solving problems of linear and non-linear optimization are NP completeness. There are developments to improve the efficiency of robotic algorithms, they are filled with requests and actual ones. In this paper, it is proposed to use deterministic and probabilistic methods for forming a priority queue of decision vector components in order to assign positive values to them. After the formation of the variant of the solution, it is possible to vectorize as if the approached solution is taken away from the record value of the goal function, which in exact algorithms is like a solution, which results in a polyp. In this paper has a method for forming a priority line for concretizing the components of the solution vector. The basis of deterministic methods is the idea of a greedy algorithm. The location in the queue is determined by the value of the corresponding component of the cost vector. The appearance of the value of non-visibility in the system of restrictions increases the priority of the component. Behind such a way, another method of determination is modified. Probability assessment probability of priorities is based on the ideas of algorithms in an ant colony and simulated annealing. The scope of probability indicates the significance of the component - a contender for a positive value. A numerical example of a small variability of the task about a knapsack has been introduced, which demonstrates the imitation of a nearby solution. [ABSTRACT FROM AUTHOR]

The cryptographic S-box is the crucial component of modern ciphers which determines their efficiency, cryptographic security, and performance. Today, the development of quantum cryptanalysis, as well as the appearance of possible attacks on cryptographic algorithms by describing them using many-valued logic functions made urgent the task of developing algorithms for the synthesis of S-boxes, which would be characterized by high quality not only when represented by component Boolean functions, but also with any other representation by component functions of many-valued logic. At the same time, most of the existing methods of synthesis of S-boxes presented in the literature are focused only on the research of their cryptographic quality when represented by component Boolean functions. In this paper, on the basis of S-boxes of length N=16, which corresponds to the strict avalanche criterion of component Boolean and 4- functions, we propose a method for synthesis of a set of high cardinality equal to J=117588 of S-boxes of practically valuable length N=256, which simultaneously corresponds the strict avalanche criterion of component Boolean functions, the strict avalanche criterion of component 4-functions, as well as the criterion of correlation immunity of component Boolean functions, i.e., they have ideal matrices of correlation coefficients between output and input vectors. The high cryptographic quality of the developed S-boxes when they are represented by component Boolean and 4-functions makes it possible to recommend them for practical use both in the tasks of increasing the effectiveness of existing cryptographic algorithms and in the development of promising ciphers, while the cardinality of the class of synthesized S-boxes allows them to be used as a long-term key. [ABSTRACT FROM AUTHOR]

One of the most important cryptographic structures, which is the basis of modern information protection systems, is cryptographically protected generators of pseudorandom key sequences, which are used in a wide variety of tasks, starting from the creation of initialization vectors, key information, and formation of the steganographic path, ending with their operation as the most important basic component of full-fledged stream cryptographic algorithms. Many of the available today algorithms of pseudo-random key sequences generators are characterized either by a quite complex software implementation structure or by insufficient cryptographic security, which makes urgent the task of developing effective cryptographically protected pseudo-random key sequences generators with a high level of stochastic quality. This paper proposes a scheme for an efficient pseudo-random key sequences generator based on a cellular automaton, as well as on such many-valued logic perfect algebraic constructions as IV-sets of quaternary bent-sequences with the maximum level of nonlinearity distance. The proposed generator is characterized by a significant complexity of the relationship between the output bits of the pseudo-random sequence and the elements of the short key on the basis of which they are generated, which determines the high level of its cryptographic security, while the number of protection levels of the proposed generator is easily scalable if necessary. Having only two binary linear feedback shift registers in the proposed scheme makes it adaptable to software implementation. The research performed made it possible to establish that the pseudorandom sequences generated by the proposed generator correspond to all stochastic tests from the NIST set, which makes it possible to recommend it for use in practice. [ABSTRACT FROM AUTHOR]

The current stage of development of information technologies is characterized by a significant increase in the use of graphic data, i.e., digital video and digital images combined with the widespread use of resource-constrained platforms, such as IoT and IoBT devices, mobile devices, as well as embedded devices. These circumstances condition the importance of the development of algorithms for encrypting graphic information, which would ensure high security for the least number of computational operations. Today, dynamic chaos theory is most often used for the development of such cryptographic algorithms. However, the optimal structure of the cryptographic algorithm for image encryption has not yet been found. In this paper, we propose a combination of the advantages of traditional SP networks and a gamma generator based on a Hyper-Chaotic Modified Robust Logistic Map to build an effective image encryption algorithm, capable of providing a high level of security. The proposed cryptographic algorithm uses high-quality S-boxes based on the Galois field transform, as well as P-boxes based on permutations generated using the Nyberg construction, while segmentation and further processing of three-dimensional image blocks are used, which allows for an increase in the diffusion effect. Numerous tests of the stochastic quality of cryptograms obtained using the developed cryptographic algorithm, as well as their comparison with the results obtained for the AES cryptographic algorithm, made it possible to establish that the developed cryptographic algorithm provides a sufficient level of information protection while requiring only two rounds. Therefore, the developed cryptographic algorithm for encrypting graphic information can be recommended for practical use, in particular, on resource-constrained platforms. [ABSTRACT FROM AUTHOR]

Copyright of Informatics & Mathematical Methods in Simulation / Informatika ta Matematičnì Metodi v Modelûvannì is the property of Odessa Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The task of path finding by an agent is one of the basic tasks and is of great practical importance. As a rule, this is an optimization task that is solved in the space of the state graph in order to minimize the length of the path. Such a task becomes more difficult and becomes even more popular if it is solved on the basis of one graph space by several agents. In this case, another practically important optimization parameter appears, which is expressed by the number of conflicts between agents. Such an abstract formulation of the task has numerous variants of formalization and a large number of approaches to its solution. In this paper, the main element of the approach is the application of the classic Dijkstra algorithm, which is executed sequentially by each agent. When finding the shortest route, each agent modifies the graph space in such a way as to reduce the probability of conflicts with subsequent agents. This approach is original and a number of computational experiments were performed to verify it using software developed for this purpose. The experiments that were conducted demonstrate the adequate behavior of the main algorithm. The work analyzes the limitations inherent in the proposed approach within the framework of the abstract formulation of the task. The directions of further development of the basic approach have been determined. [ABSTRACT FROM AUTHOR]

Copyright of Informatics & Mathematical Methods in Simulation / Informatika ta Matematičnì Metodi v Modelûvannì is the property of Odessa Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Informatics & Mathematical Methods in Simulation / Informatika ta Matematičnì Metodi v Modelûvannì is the property of Odessa Polytechnic University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At a time when the use of digital content in all spheres of life is constantly growing, the ability to verify the authenticity of digital files, in particular digital images, is extremely important in protecting information from integrity violations. In the information war, photo fakes are always used to achieve certain, often criminal, goals. Both society as a whole and individuals must take care of information security and protect their information space from unverified information. Modern methods of detecting violations of the integrity of graphic information to some extent address some issues of information security, however, they are not universal and often require development, improvement, additional research and so on. Thus, existing methods for detecting such a common method of image falsification as scaling are effective only in cases where the falsified part is enlarged, however, when reducing part of the image, they are not effective. Moreover, in open printing the problem of detecting reduced scalable parts of the image is not covered. Therefore, the aim of this work is to increase the efficiency of scaling detection as digital image falsification by developing an algorithm for detecting scaling with a negative coefficient. In this paper, the method of error level analysis is adapted to detect reduced parts of the digital image. The efficiency of the adapted method in terms of errors of the 1st and 2nd kind was: errors of the 1st kind - 2%, 2nd kind - 7%. In addition, it has been found that this method is also effective in detecting simultaneously scalable (reduced) and moved parts of a digital image. This method detects artifacts (errors) in the digital image, which occur when reducing its part - the falsified area has a higher high-frequency component than the rest of the image, which is amplified under the influence of compression after saving the falsification in a lossy format. [ABSTRACT FROM AUTHOR]

This paper contains the results of studies of the cognitive model developed information technology interdependence and interrelation of complex technical systems to assess their vulnerability. A general block diagram of a ship interconnectedness of complex technical systems. The interaction of ship power plant units, the power supply system of the ship and ship's auxiliary systems in extreme emergency situations. Based on the results of research developed an information processing model of cognitive functioning marine interdependence of complex technical systems. In accordance with the established algorithm vulnerability assessment information elements of the cognitive model calculated the coefficients of the structural vulnerability of its elements. The calculation results have allowed to identify the most critical elements of the model in terms of reliability. The results of research and development will improve the efficiency of operation of complex technical systems that provide high-quality prediction of the reliability of their operation in extreme emergency situations. [ABSTRACT FROM AUTHOR]

This paper is devoted to steganalysis algorithm determining presence a secret message embedded into digital image which is stored in compressed or uncompressed form. The algorithm is based on the analysis of pairs of colors and uses the method of modifying the least significant bit. [ABSTRACT FROM AUTHOR]

The paper focuses on general method of predictive control of modern multi-service networks, which is a major component includes algorithms for the identification of structural models of regular components (trends) of the observed processes. The general structure for predictive control of aircraft communication systems is described. The general view of the structural identification algorithm is discussed. [ABSTRACT FROM AUTHOR]

The paper suggests a new approach to determine the intensity of failures and restorations of complex technical systems of arbitrary nature, based on the application of probability theory, mathematical statistics, simulation and function approximation. Finding failure rates and restorations in the form of functional dependencies allows model the function of readiness. [ABSTRACT FROM AUTHOR]

The paper focuses on new steganographic algorithm development. Proposed algorithm is stable to compression, including high rate compression, and based on singular vectors insensitive of image matrix blocks which corresponding to maximal singular values. Algorithm is polynomial of degree 2. The results of numerical experiments confirm the efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In this paper, a new approach to solving a problem of steganography algorithm stability to cover-attack is proposed. The algorithm is based on the general approach to analysis of state and functioning of information system which was previously developed by the author. Consequently, we obtain the sufficient conditions for low-sensitivity of stegano message to compression while ensuring the reliability of perception. The proposed approach automates the process of analyzing the existing or emerging steganography algorithms from viewpoint of its resistance to compression. This became possible due to estimation of singular values perturbation of cover's matrix during the stegano transformation process. Additionally the proposed algorithm allows a priori selection of less sensitive to compression stegano messages from their variety. [ABSTRACT FROM AUTHOR]

The relevance of the work lies in the need to increase the efficiency of computer modeling through the use of progressive hardware and software parallelization and synchronization of calculations on modern computers with multi-core architecture. The purpose of the work is to increase the speed of computational algorithms of Thomas algorithm by using advanced technologies for programming parallel computing. Serial and parallel algorithms for software implementation of Thomas algorithm have been developed; a comparative evaluation of the implementation efficiency (speed of execution) of these algorithms by means of an open standard for parallelizing OpenMP programs for a significant (up to 5×107) SLAE order was performed. The use of progressive programming technologies in the implementation of the indicated methods for solving SLAEs made it possible to increase the computation speed by 1,9-2,9 times. The obtained results correspond with the known literature data. In this work, the time values of the software implementation of sequential and computational algorithms of Thomas algorithm for SLAEs of significant order were obtained for sequentially and parallelized into two streams using OpenMP tools. The expediency of such parallelization for SLAE of the order of more than 2,5×105 is shown. The practical significance of the work lies in the use of the results obtained in the numerical study of stationary and non-stationary, linear and nonlinear processes in mathematical modeling problems, where the multiple solution of a significant order SLAE is the most resource-intensive stage. [ABSTRACT FROM AUTHOR]