A constructive method is proposed for the synthesis of cryptographic substitution boxes (S-boxes) satisfying both the strict avalanche criterion and the high nonlinearity criterion, where smaller length S-boxes and highly nonlinear bent functions are used as a source material. In addition, effective algorithms for the reproduction of the above S-boxes have been developed.

The article is devoted to research of the application of artificial intelligence in the military sphere. Due to the rapid development of information technologies and the growth of data volumes, the use of artificial intelligence is becoming more and more relevant for the effective application of the latest technologies for solving military tasks. The purpose of the research is to determine how the use of artificial intelligence can help improve the performance of the military. The research hypothesis is that the use of artificial intelligence in military operations can lead to improved efficiency and accuracy of decision-making. The paper discusses the main possibilities of using artificial intelligence in the military sphere and the specifics and advantages of its use. Research indicates that the implementation of artificial intelligence can help identify risks and improve the planning and forecasting of military operations, as well as enable the automation of logistics accounting and analysis. To achieve this goal, a research methodology was used, which included the analysis of literary sources and conducting research based on information about the application of artificial intelligence in the military industry. During the analysis of the specifics of the use of AI in improving the activities of the military, the areas of its successful implementation were researched: video surveillance, national security and the fight against terrorism, military logistics, autonomous and semi-autonomous vehicles, cyber security, simulators for military training, AI operations on the battlefield, medical assistance on the battlefield. It has been found that AI has great potential for effective implementation in the military sphere because the implementation of AI algorithms helps in solving military tasks potentially dangerous to human health and improves the effectiveness of weapons. The implementation of AI technologies in various components of military activity mostly shows significantly higher efficiency when compared to other technologies. In general, technological innovation in combination with AI is currently becoming a decisive factor in determining a successful outcome on the battlefield, but it requires careful preparation and consideration of risks in the process of its implementation.

The widespread use of block symmetric ciphers in modern information security systems makes the task of increasing their efficiency urgent, as well as the task of synthesizing high-quality cryptographic primitives used in modern block symmetric ciphers, primarily S-boxes. In particular, the S-boxes must have good avalanche characteristics not only of their component Boolean functions, but also of the component functions of many-valued logic. In this paper, we propose a recursive method for the synthesis of large lengths S-boxes that satisfy the strict avalanche criterion of component 4-functions. As a raw material for the construction of such an S-boxes, small-length S-boxes are used that satisfy the strict avalanche criterion of component 4-functions. In the constructed set of S-boxes that satisfy the strict avalanche criterion of component 4-functions, we found those that simultaneously satisfy the criterion of the maximum avalanche effect of component Boolean functions. The avalanche characteristics of these S-boxes are of high quality both from the point of view of their representation with help of Boolean functions, and from the point of view of their representation using 4-functions. These S-boxes can be recommended for practical use to modernize existing symmetric cryptographic algorithms, as well as to build new perspective ciphers.