Research on the compromising electromagnetic emanations from digital signals

Information can be compromised by electromagnetic emissions from running information technology equipments. Most data in these equipments are processed or transmitted as digital signals, and they´re of vital importance to ensure the emission security of digital signals. As the data rate goes faster and faster, the edges of the digital signal get sharper, which means it contains more high-frequency components and can generate electromagnetic emission by small-sized antenna-effect components of the equipment. The level fluctuation process may be recovered or demodulated by analyzing the intercepted electromagnetic emission, thus restore the digital signal and course information security problem. Characteristics of the digital signal are analyzed in depth and the electromagnetic emissions of digital signals with different wave forms are researched. Finally, compromising emanations examples of digital signals with different characteristics are analyzed.