Research On Monitoring Platform Of Computer Video Leaking Signal

The increasing development of computer, network and electronic information technology keeps on accelerating the process of informatization. Though electronic devices facilitate our life, they will cause electromagnetic leaking when working, which affects the information safety. The technology of electromagnetic leaking research is called'Tempest' in the world, which includes the principle of the compromising emanation in information processing devices, the defense technology of information compromising emanation, the technology of detection and reconstruction for valid information, etc.. Aims at the technology of detection and reconstruction for valid information, the analysis and research of the computer video leaking has been finished in this thesis.Based on the principle of the electromagnetic leaking, the electromagnetic leaking source and the emanation principle is demonstrated. Video Display Unit is the major electromagnetic leaking source in computer systems. The video information in Video Display Unit can easily be intercepted and reconstruction. After the discussion of the radiation principle of different electromagnetic leaking source and types of signal in the computer video-display system, it can be known that computer video leaking signals are composed of video data and horizontal synchronization signals. The principle of video signal reception is explained, after the character analysis of these two signals and simulation experiment.When dealing with technique problems existed in computer video leaking signal detection system, solutions are put forward in this thesis:1, to solving the problem of weak signal extraction, applying the extraction method for horizontal synchronization signals based on the correlation technique and de-noising method for video leaking signals based on the one-dimensional wavelet transform.2, to solving the problem of strong noise in the reconstruction of computer video leaking signals, applying the multi-frame average de-noising filter and the wavelet transform filter. These solutions play an important role at the computer video interception and reconstruction.With rapid development and refreshment of the technology, different methods and devices are applied to the electromagnetic leaking detection and measurement, including analog and digital methods; traditional and virtual instruments. The key work of this thesis is design and implementation of hardware and software structure for the video leaking detection and measurement platform based on the PXI technology. Resulting from the modularized hardware and self-defined software structure, the character of practicability, flexibility and expansibility can be applied to this platform. Offering the effective experimental method and technique, the function of the electromagnetic-leaking detection and measurement has been implemented on this platform. After practice and summarizing, the improvement solution for the problem of transmission speed and computational efficiency is finally proposed in the thesis.