Research On Leakage Preventing Technique For Computer Video System Based On DVI

This paper analyzes the background and the research conditions of electromagnetic information leakage from computer system firstly, 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, according to visual inertia and mixed color law, this paper puts forward a new method of preventing interception and capture: complementary randomizing. The author introduces spectral correlation coefficient and structural similarity index (SSIM) from two aspects of the frequency domain security and image display quality, conductes detailed simulation analysis and evaluation, shows that complementary randomizing increased the display quality of image processed greatly while reached the requirements of leakage preventing, and chooses the maximum value of pseudo-random sequence between 127 and 63 as the most appropriate range. At the last, the simulation software of digital video information leakage preventing is composed with VC and C++, and typical examples are verified by simulations.