Abstract: The subject of research is the steganographic method of embedding information in digital images. Steganography is capable of hiding not only the content of information, but also the very fact of its existence. The paper considers one of the most important problems in the development of steganographic methods - the secrecy of the transfer of protected information. Stealth is not only visual or auditory indistinguishability of a digital media resource from a media resource with embedded information, but also statistical indistinguishability. Special attention is paid to preserving the spatial statistical dependence between the image pixels. The methodological basis of the research is the methods of mathematical statistics and image processing theory, as well as image distortion metrics. The novelty of the research lies in the development of a new method of embedding information in static images. The authors consider in detail the problem of applying the moving average autoregression process to represent the statistical dependence of image pixels. It is shown that the proposed method allows you to embed information into digital images without significant distortion.

Abstract: The research subject is the steganographic methods of information protection. There are two key ways to protect information – cryptographic and steganographic. Cryptographic methods conceal only the contents of the transmitted information. At that, the fact of transmission of the codified data can draw the attention of an intruder who can use the successful cryptographic attacks, aimed at the loss of confidentiality. Steganographic methods hide not only the contents of the information sent, but also the very fact of sending. Steganography and cryptography are complementary methods, which, used together, can significantly increase the safety of the transmitted data. Therefore, it is necessary to develop not only cryptographic, but also steganographic methods of data protection, which should be resistant to the detection of the process of sending. The research methodology contains the passive methods of analysis of detection of the information, embedded in the image, including statistical and visual methods. The novelty of the study consists in the development of the steganographic system of data protection on the base of the proposed original algorithm of embedding the information by the coverage of the image block in lines and columns. The authors demonstrate that this steganographic system maintains its resistance to passive steganoanalytic attacks when the blocks up to 24x24 pixels are covered, and with this coverage degree it is more resistant than the standard and the advanced steganographic methods based on the direct spectrum broadening. 

Abstract: The subject of the research is the steganographic information protection system (SIPS) based on the method of the direct spectrum spread with minimum change of image pixels and maximum image fill. Special attention is paid to the problem of creating a SIPS with a blind decoder because the original image strongly influences the correct extraction of in-built information. The authors examine such aspects of the topic as the application of the autoregression process and error-correcting codes in order to reduce the number of errors during extraction of in-built information. The methodological basis of the research involves methods from the theory of noise-resistant coding, methods of digital image processing, and methods of mathematical statistics. The novelty of the research is caused by the fact that the author defines the optimum block size (32x32 pixels) that enables the two-dimensional autoregression process (AP) to provide the maximum number of correctly extracted in-built bits. Moreover, the authors analyze efficiency of applying BCH Code, Reed-Solomon code and LDPC code for restoration of in-built data. They demonstrate that LDPC code combined with the algorithm of 'soft' decision making 'Belief propagation' option is the most efficient for reducing the number of errors when extracting in-built information by the stenographic method on the basis of the direct spectrum spread.