The presented method of encoding and steganographic embedding of a series of bits for the hidden message was first developed by modifying the digital platform (bases) of the elements of the image container. Unlike other methods, steganographic coding and embedding is accomplished by changing the elements of the image fragment, followed by the formation of code structures for the established structure of the digital representation of the structural elements of the image media image. The method of estimating quantitative indicators of embedded critical data is presented. The number of bits of the container for the developed method of steganographic coding and embedding of critical information is estimated. The efficiency of the presented method is evaluated and the comparative analysis of the value of the embedded digital data in relation to the method of weight coefficients of the discrete cosine transformation matrix, as well as the comparative analysis of the developed method of steganographic coding, compared with the Koch and Zhao methods to determine the embedded data resistance against attacks of various types. It is determined that for different values of the quantization coefficient, the most critical are the built-in containers of critical information, which are built by changing the part of the digital video data platform depending on the size of the digital platform and the number of bits of the built-in container.

The estimation of quality of the restored images on the basis of value of a peak ratio signal/noise for test images is provided. The estimation of compression coefficients is provided. The method of efficiency estimation of the advanced technology of compression on the base of method of invariant spatial coding on the basis of value of integral metric - absolute increase of delivery time in case of integration of advanced technology on into the aviation communication systems is developed.

Methods for verifying and identifying the operator by the features of the formation of biometric features of a speech signal in control systems of unmanned aerial systems are proposed. A method has been developed for the effective width of the spectrum of a speech signal, which allows identification and verification of the operator of an unmanned aerial vehicle based on an analysis of the informative components of voice prints under conditions of a high level of interference of various origins. A method has been developed for the highest informational weight of the fundamental tone, which is based on the use of the most informative components of the spectral representation of the prints of a speech signal. The first method allows to identify the operator of an unmanned aerial vehicle by the informative components of the spectral representation of the fingerprint of a speech signal under conditions of a high level of interference. High indicators, which are achieved by using this method, are obtained due to the uniqueness of the selected feature space, which retain their characteristics even with a fairly high level of interference. The second method provides speaker identification of an unmanned aerial vehicle by a specific space of unique voice features. The frequencies of the fundamental tone and overtones were chosen as the basic features. Such an approach to solving the identification problem provides a high probability of determining the operator with the existing rather high level of interference and reduces the processing time of information in comparison with the effective spectrum width method.The creation of control methods and models for unmanned aerial systems provides an increase in the level of noise immunity and safety of control systems from interventions by an unauthorized operator. Using operator identification methods allows to create a system for restricting access to the aircraft control process and thereby ensure the continuity of the operation of the information management system for unmanned aerial systems

Direct spread spectrum technology is traditionally used in radio communication systems with multiple access, for example, in CDMA standards, in global satellite navigation systems, in Wi-Fi network wireless protocols, etc. It ensures high security and reliability of information transfer. In addition, spread spectrum technology provides the transmitted signals with a noise-like appearance, thus hiding the semantic content of the messages. We researched this technology for other implementations. The purpose of our study was to investigate new technologies for hiding data in multimedia files. In particular, we investigated the direct spread spectrum in the context of the development of methods for hiding data in audio containers. We considered various spreading sequences (chip codes) and also explored their use for hiding information in audio files. We conducted experimental studies and estimated the bit error rate (BER) in the recovered data. The article also evaluates the distortion of an audio container by the peak signal-to-noise ratio (PSNR). The results of our research enable us to find out which method of forming chip codes gives a lower BER with equal PSNR. We provide recommendations on the formation of spreading sequences to reliably and safely hide informational messages in audio files.

This paper reports a method of protection against zero-day attacks using SandBox technology based on the developed analytical model with a probabilistic ranking of information system states. The model takes into consideration the conditions of a priori uncertainty regarding the parameters of the destructive flow on the system, accounting for the typical procedures of the network SandBox. The proposed model of information system states makes it possible to analyze and track all possible states, as well as assess the level of security in these states, and the probability of transitions into them. Thus, it is possible to identify the most dangerous ones and track the activities that caused the corresponding changes. The fundamental difference between this model and standard approaches is the weight coefficients that characterize not the intensity of random events but the intensity of transitions between states. Direct implementation and application of the proposed analytical model involved the technology of multilevel network "SandBoxes". The difference from other popular anti-virus tools is the use of a priori mathematical threat assessment, which makes it possible to detect influences that are not considered threats by classical systems until the moment of harm to the system. The combination with standard security tools makes it possible to separately analyze files that are too large in size, whether they enter the system not through a common gateway controlled by the network "SandBox" but from the external media of end-users. The implementation of the developed analytical model has made it possible to improve the level of protection of the corporate network by 15 %, based on the number of detected threats. This difference is explained by the inability of classical software to detect new threats if they are not already listed in the database of the program, and their activity is not trivial

The problem of nonlinear substitution generation (S-boxes) is investigated in many related works in symmetric key cryptography. In particular, the strength of symmetric ciphers to linear cryptanalysis is directly related to the nonlinearity of substitution. In addition to being highly nonlinear, S-boxes must be random, i.e., must not contain hidden mathematical constructs that facilitate algebraic cryptanalysis. The generation of such substitutions is a complex combinatorial optimization problem. Probabilistic algorithms are used to solve it, for instance the simulated annealing algorithm, which is well-fitted to a discrete search space. We propose a new cost function based on Walsh–Hadamard spectrum computation, and investigate the search efficiency of S-boxes using a simulated annealing algorithm. For this purpose, we conduct numerous experiments with different input parameters: initial temperature, cooling coefficient, number of internal and external loops. As the results of the research show, applying the new cost function allows for the rapid generation of nonlinear substitutions. To find 8-bit bijective S-boxes with nonlinearity 104, we need about 83,000 iterations. At the same time, the probability of finding the target result is 100%.