Electronic Protection / Chapter 77, The Handbook of Information Security

Abstract

Electronic protection involves methods of preventing spies from stealing secrets from the electromagnetic emanations of your information systems, as well as methods of preventing saboteurs from incapacitating or destroying your information systems using electromagnetic radiation. We discuss the kinds of threats and what can be done to reduce or prevent them. Particular weaknesses are video monitors, keyboards, and cables. Electromagnetic shielding is helpful, but requires special additions to computer hardware. Source suppression, noise generation, encryption, deliberate irregularity, and deliberate deception can also help against spies but require careful planning. Bug detectors can alert you to electronic devices that may be eavesdropping, but do not always work. As for electromagnetic sabotage, similar shielding methods can protect against it, but backup methods are important, including current limiters.