Technology Of Preventing Compromising Emanations From Digital Video Signal Based On DVI

This paper firstly describes the background and the research conditions of electromagnetic information leakage from computer system, and explains that traditional technologies are not applicable to new digital video interface DVI (Digital Visual Interface), then points out the need of studying new technology preventing compromising emanations from video signal. Following that the basic principle, signal characteristic and main differences from traditional analog video interface of DVI are introduced, in addition, the principles of electromagnetic radiation leakage and video information interception of corresponding displays system are analyzed.Based on before analysis, combining with frequency spectrum characteristic of leakage information, this paper puts forward a new method of preventing interception and capture: randomizing, the frequency and time domain readability characteristics of digital video image are irrespectively researched in detail, and two constraint conditions are brought forward, finally the vital conclusion that holding 2 to 3 importance bits is proper when randomizing is got. Because generation algorithm of random numbers is the key to randomizing, then the paper analyzes several kinds of generation algorithms, and selects multiply congruential algorithm at last. Then the simulation software of digital video anti-interception is made using this arithmetic by VB and MATLAB, at the same time, a lot of simulations are made to validate before relevant conclusions finally.