Method Of Anti-leakage Of DVI Video Information Based On Spread Spectrum

Signal security is very important in the research of computer security. The video information, which contains a lot of valuable information, is transmitted by a very long cable. The unacceptable radiation makes it unsafe in the computer system.The time and frequency characteristics of the video signal (VGA), the ways of its leakage, and the methods of anti-leakage are reviewed at the beginning of this paper. The differences between the video signal of DVI and VGA are analyzed, especially the spectrum of signals before and after TMDS coding and decoding. The conclusion that the video signal of DVI does leak information is obtained by simulating the spectrum of the image which only contains black and white characters. Besides, the places of video information leakage are obtained. The applicability of the anti-leakage methods based on VGA is analyzed, and the anti-leakage method based on spread spectrum of DVI is put forward.The algorithm of the spread spectrum of digital video signals is presented in this method, based on the pseudo-random sequence theory. The luminance representation and similarity are used to evaluate the quality of the image after spreading spectrum. Combined with the receiver bandwidth, received intensity, and antenna correction factor, the key parameters of the algorithom are confirmed. And also, the total solution of anti-leakage of video information based on DVI is obtained. In the end, verification experiments are done to prove the conclusions above.