Mathematical Model of the System of Active Protection Against Eavesdropping of Speech Information on the Scrambler Generator

The development of reliable systems for protecting speech information that can protect it from being intercepted by cybercriminals is a fundamental task of the security service of organizations and firms. For these purposes, active jamming systems are used at the border of the controlled area. The main element of such systems is noise generators. However, in many cases, “white” noise and its clones are used as interference, which makes it possible for an attacker to gain unauthorized access. The structure and mathematical model of a speech information protection system based on a scrambler-type noise generator is proposed. The transition in such systems of protection of speech information to this structure allows to abandon the outdated, ineffective in modern conditions, energy noise of speech information and move on to a more productive method – information (linguistic) masking. An analysis of the destructive effect of this type of interference shows its high resistance to modern methods of mathematical processing of digital phonograms (wavelet transform, correlation-spectral analysis, etc.), filtering interference, and dividing the voices of speakers. Studies of the mathematical model in the environment of Matlab 15 R2015a/Simulink show the high efficiency of such a protection system and a decrease in the signal-to-noise ratio with a residual speech intelligibility of 0.1 by 6...9 dBA. This leads to a decrease in noise in the room and beyond, which positively affects the bioacoustic characteristics of the premises, improves working conditions and staff productivity, and also reduces the unmasking performance of the objec