Methodological aspects of assessing technical security speech information in designated premises

DOI: 10.31673/2412-9070.2022.031215

Abstract

Taking into account the continuous development of methods and means of interception of acoustic information, ensuring the technical protection of such information from leakage through technical channels remains an urgent task. The task of protection against leakage is to block all possible channels and neutralize means of interception.
Quite often, in the process of discussions during meetings, information is expressed emotionally, with increased tension of the vocal cords (the so-called effect of forcing speech). At the same time, in addition to increasing the overall speech level, there is also a redistribution of energy within the spectrum, the energy maximum is shifted to the high-frequency region, which affects the contribution of frequency bands to overall intelligibility.
Thus, there is an urgent need to develop a perfect method for assessing the security of speech information in dedicated premises.
At the same time, the method should be independent of the structure and principles of operation of systems of technical protection of speech information with limited access, and take into account the possibilities of modern methods of digital processing of phonograms.
The purpose of the publication is the formation of a methodical approach to the assessment of the technical security of speech information with forced sounding in a dedicated room against leakage through technical channels.
The need to improve the methodology for assessing the technical security of speech information with forced sounding in designated premises is substantiated. A study of the difference between the spectrum of calm and forced speech was conducted, and the results of research on determining the width of the frequency spectrum of forced speech were given. In the course of research, it was determined that the spectrum of 70 Hz...10 kHz should be used during testing. The levels of the test acoustic signal, providing a confidence probability of 0,95, are 74 dB for quiet speech and 85 dB for forced speech.
This approach can be used if it is necessary to assess the object’s security according to increased security requirements.

Keywords: speech signal; technical leakage channel; speech intelligibility; information protection,; assessment of technical security of speech information.

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