Vovk O. Methods to improve the stability and capacity of covert communication systems

Object - the processing, protection, and secure data transmission in telecommunication systems and networks. The purpose - to improve the efficiency of covert communication in telecommunication systems based on steganographic method with high levels of stability and capacity. Methods - set-theoretic approach, digital signal and image processing, coding theory, multi-criteria optimization. Results - the comprehensive measure of the steganographic system is developed that allows to obtain quantitative values of multi-criteria analysis steganographic methods to meet the requirements for embedding methods depending on the purpose of the system and taking into account the importance of the quality indicators; the steganographic method of embedding data into image wavelet coefficients is improved by integrating the principles of frequency method of Koch-Zhao, as well as increasing the capacity of steganographic system by expanding integration diagonal and use of two wavelet transform matrices to hide the message; the steganographic method of embedding data into image is developed, which is based on a consistent application of the discrete cosine and the discrete wavelet transform and uses advanced methods of improving the stability of steganographic systems to geometric attacks and pre-processing of the information to be embedding. It is introduced - in academic activity, subject "Protection of information in telecommunication systems", "Theory of telecommunications", "Fundamentals of steganographic information protection". Sphere of application - telecommunication networks