Analysis And Processing Of Computer Video Electromagnetic Leaking Signal

With the rapid development of information, computers are widely applied in different industries. However, electronic devices used for processing of information will leak out information by means of electromagnetic radiation and the leaking information can be eavesdropped and reconstructed within a certain range. The securities of information got threaten.In the computer system, CRT is the display equipment that radiates most strongly, having most visible information, and the video information can be intercepted most easily. This thesis studies electromagnetic information leakage mechanism on the basis of electromagnetic radiation. Electromagnetic information leakage mechanism of electron beam in cathode ray tube (CRT) is analyzed as a special example. The video information leakage mechanism and synchronization characteristic is analyzed and the theory basis to intercept video leakage information is pointed out. This thesis mainly researches the signal processing techniques of video leakage information. The leakage information, sampled and memorized by the high precision memory, processed by the computer to process the signals, analyze the characteristic, extract the synchronization characteristic signals.This thesis offers the reliable basis for the TEMPEST protecting technology, receiving and recovering technology from the video leakage information and designing computer TEMPEST products.