Information defence by method of statistical irreversible transformations of informative radiations

Abstract

Modern information devices allow the detection of spurious signals originating from the activity of computer equipment at distances of tens or hundreds of meters and sometimes more. In practice, to achieve the required level of defence, it is necessary to resort to screening the radiations and limiting the spatial availability of these radiations to the potential malefactor or to increase the noise level of all possible frequency bands of potentially informative radiations. The first variant is very expensive and is not always realizable, and the second variant results in a problem with the electromagnetic compatibility of all complex electronic equipment in the office. Therefore, at present, significant attention is given to non-power ways of active privacy from leakage of information on spurious electrical radiation channels. In comparison with noise interference, masking stochastic interferences, formed from useful signals by the method of statistically irreversible transformations, are functionally coupled to the signal and contain the so-called undistorted remainder of the signal and the interfering component. From the point of view of the useful signal, there is an interference of two components (the useful signal and the undistorted remainder to which is added the interfering component) and the given. interference is simultaneously multiplicative and additive. The fluctuating part of the interfering signal, called the interfering component, influences additively on the signal and diminishes the signal-to-noise ratio.