Method and device for judging existence of character information in electromagnetic leakage signal

Abstract

The invention provides a method and a device for judging existence of character information in an electromagnetic leakage signal. The method comprises the following steps: performing wavelet domain sparsity on the electromagnetic leakage signal and acquiring a sparse signal; equally dividing the sparse signal into n sub-straps, and acquiring sectionalized sparsity, wherein the sectionalized sparsity is the number of null points in each sub-strap signal, and n is an integral number greater than 1; performing autocorrelation on the sectionalized sparsity, acquiring the peak point, which is most approximate to the null point, in autocorrelation, and acquiring the character-gap-character characteristic frequency according to the peak point; judging whether the frequency is less than a preset first threshold or not; if the frequency is less than the preset first threshold, determining that the character information is contained in the electromagnetic leakage signal, wherein the preset first threshold is a frequency corresponding to a word size of eight. According to the method, the existence of the character information in the electromagnetic leakage signal can be automatically judged, and reference is provided for subsequent electromagnetic leakage protection work.

Description

technical field [0001] The invention relates to the technical field of electromagnetic leakage signal detection of information equipment, in particular to a method and device for judging whether an electromagnetic leakage signal contains text information. Background technique [0002] At present, information equipment will produce different degrees of electromagnetic leakage during the working process. This electromagnetic leakage signal may contain sensitive information processed by information equipment. Through specific equipment and signal processing methods, the electromagnetic leakage signal can be intercepted and restored. Sensitive information in it, which threatens the security of the information. [0003] Electromagnetic leakage signals can be divided into two types: electromagnetic leakage signals containing text information and electromagnetic leakage signals not containing text information. Electromagnetic leakage signals containing text information have a high...

AI Technical Summary

Problems solved by technology

[0009] However, based on the principle of relevant detection, it is impossible to judge whether the electromagnetic leakage signal contains text information.

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