Electromagnetic Radiation and the Computer Systems Data Security Problem

This problem stems from two basic facts. The first is connected with the physics of the processes taking place in digital electronic equipment. The second is due to the way of representing, processing, and transferring the information. The presence of current pulses in power buses due to the impulse character of the functioning of the digital integrated circuits, the existence of inductive and capacity parasite connections, which cause the emergence of high frequency current, and the impulse character of the currents in connecting cables and interface chains all cause the emergence of parasite electromagnetic emissions, which are transmitted as electromagnetic waves. At the same time, in the cables of the power supply alternating currents are induced in such a way that the power supply circuitry becomes a source of secondary wide band emission.