Wireless Computer Keyboard Electromagnetic Radiation Signal Information Security Research

With the development of scientific technology, the wireless keyboard hasbeen the growing popularity and has become the main input device forcomputer users, is often used for input user's the various of account informationand so on, these information once be obtained by the other will cause hugelosses. The working principle of wireless keyboard decided it will definitely topose an information security threat for the computer.The attackers collect information from the radiated signal during theexchange between wireless keyboard and host computer, and get information,resulting in the computer useful information leakage. This is the researchcategory of TEMPEST technology. In the article, we carry out searching thetechnique of interception and restore about the wireless keyboard radiated signalfor raising and resolving wireless keyboard information security problems andprotective measures. The main work is:First, through the study of the generating process of keyboard scan code,the specific content of wireless keyboard communication agreement and thebasic principle of frequency hopping technology etc., we understand theworking principle of the wireless keyboard.Second, based on the research of the radiated electromagnetic wavemechanism of the aerial, we analysis antenna's signal radiation and receivemodel. We discuss the electromagnetic information leakage about two digitalsignals for the pulse signal and the clock signal which were produced by thewireless keyboard. We research the radiated signal characteristics of thewireless keyboard.Third, we select the experimental environment and equipment. We buildthe test platform, use the antenna and spectral analyzer and other equipment,collect the wireless keyboard radiated signal. By analyzing the experimentaldata, we search out the characteristics of the radiated signal that can be used todistinguish different wireless keyboard and button, lay the foundation for the further repetition of technology research.Fourth, combined with the existing security protection technology and thework principle of wireless keyboard, we put forward several feasibleinformation security protection technologies.