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The article presents the experimental parameter evaluation results of the electronic documents marking algorithm, based on interword distances shifting. The developed marking algorithm is designed to increase the security of electronic documents containing textual information from leakage through channels caused by printing, scanning or photographing, followed by sending the generated image. The algorithm analyzed parameters are such characteristics as embedding capacity, invisibility, undetectability, extractability and robustness. In the course of embedding capacity estimation of the developed algorithm, analytical expressions are given that make it possible to calculate the maximum achievable embedding capacity value. The obtained quantitative estimates and the experiments carried out made it possible to substantiate the admissible values choice of the embedded marker. To determine the embedded information invisibility in the source document, an invisibility and undetectability assessment of the embedded marker was carried out. During the expert evaluation, the developed algorithm invisibility to visual analysis was substantiated, as well as the absence of significant statistical deviations in the distribution of the analyzed parameters in the process of assessing the resistance of the developed marking algorithm to the potentially best steganographic analysis method. The quantitative extractability of the developed marking algorithm was carried out by assessing the extraction accuracy. The analysis performed showed accuracy high values of marker extraction from scanned images, which makes it possible to reliably extract embedded data, as well as determine directions for improving the extraction accuracy from photographed images. In the assessing process the stability of the developed marking algorithm to the transformations implementation and distortions introduction, the main robustness parameters of the developed marking algorithm to the printing, scanning and photographing processes are determined. Conclusions are formulated on the using possibility the developed marking algorithm and directions for further researches are identified.

The purpose of research – development of a more advanced Windows NT family access control mechanism to protect against information leakage from memory by hidden channels. The method of research – analysis of Windows NT family models of mandatory access control and integrity control, modeling of access control security policy for specified security properties, automatic verification of models. The Lamport Temporal Logic of Actions (TLA +) used to describe the model and its specification is used. TLA+ allows automatic verification of the model with the specified security properties. The result of research – revealed the main limitations of the existing mandatory integrity control of operating systems of the Windows NT family. A set of structures of a multilevel model has been developed, reflecting the attributes that are significant for modeling the process of access of subjects to objects. The key mechanisms of access control in the operating system are modeled: management of users, groups, subjects, objects, roles, rights, discretionary and mandatory access control, mandatory integrity control - multilevel control of subjects’ access to objects. The model defines a mechanism for controlling the creation of subjects based on executable files to organize an isolated software environment. The values of the attributes of the model variables for the initialization stage are determined. The invariants of variables correctness in the process of verification and subjects to objects safe access are developed. The model was specified using the TLA + modeling language and verified.

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Despite the availability of data leak detection and prevention tools, there are currently a growing number of confidential data leaks through the fault of insiders. One of the possible data leak channels is encrypted or compressed data transfer, because the existing data leak detection tools use content data analysis methods. This article presents an algorithm of detecting encrypted and compressed data that is based on the statistical model of pseudo-random sequences and allows detecting encrypted and compressed data to an accuracy of 0.99.