【作者】 唐懿文；

【导师】 薛永祺；

【作者基本信息】 华东师范大学 ， 通信与信息系统， 2011， 博士

【摘要】 随着计算机、网络和电子信息技术的发展,信息化进程不断加速,电子设备为我们生活提供了便利,然而任何电子设备工作时都会产生电磁泄漏,影响信息安全。在国际上研究信息电磁辐射泄漏的技术被称为"TEMPEST"。TEMPEST技术的研究内容主要包括：信息处理设备的泄漏辐射机理、信息泄漏辐射的防护技术和有用信息的接收和重建技术等。本论文着眼于TEMPEST技术中有用信息的接收和重建技术,对计算机系统视频信息泄漏进行研究和分析。文章在电磁泄漏机理基础上,讨论了计算机系统中存在的电磁辐射源及其辐射原理,指出视频显示部件为计算机系统中主要电磁泄漏源头,其包含的视频信息容易被截获并恢复。在对计算机视频显示系统中不同辐射源的辐射原理和信号类型进行了剖析后,指出泄漏视频信号主要分为视频数据信号和行同步信号。通过对两者的信号特征分析和仿真实验,阐述了视频信号接收的原理。本文对视频泄漏信号接收系统中存在的一些技术难题进行了研究,并提出了解决方法：1、对于弱信号的提取问题,本文提出了基于相关性技术的行同步信息提取方法和基于一维小波变换技术的视频泄漏信号去噪方法；2、对于计算机电磁辐射泄漏图像重现过程中遇到的大噪声问题,本文提出了采用多帧平均去噪滤波器和基于小波技术的滤波器两种去噪方法。这些技术在系统中起到了举足轻重的作用,对视频信号窃取与恢复有重要意义,随着技术的不断更新,从模拟技术到数字技术,从传统仪器到虚拟仪器,不同的方法被应用到电磁泄漏测试中。本文研究的重点是基于PXI技术的视频泄漏信号监测平台软硬件架构的设计及实际应用。基于模块化硬件和软件自定义的架构,使该监测平台集实用性、灵活性和可扩展性为一体,为泄漏信号的监测工作提供了一个完整的实验平台。该平台中提供了有效的实验方法和技术,实现了泄漏视频信号的监测功能。经过实践和总结,本文对系统平台的传输速率和计算效率的问题提出了改进方案。更多还原

【Abstract】 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.更多还原