Van Eck phreaking

Van Eck phreaking refers to any form of signal interception of side-band electromagnetic emissions from electronic devices, including everything from monitors to keyboards and printers. It is named for Wim van Eck, a Dutch researcher at the Dr. Neherlaboratorium of the Netherlands PTT, who published the first widely-known non-classified technical analysis of video display interception in a 1985 paper entitled "Electromagnetic Radiation from Video Display Units: An Eavesdropping Risk?" The phenomena was well-known at that point in security circles, having been the object of research as early as the Second World War by Bell Labs, later expanded by the United States Naval Research Laboratory and the National Security Agency (as TEMPEST); van Eck's larger contribution was the revelation of how the interceptions could be accomplished at low cost by private actors.

Reading

• van Eck, Wim (Dec. 1985), "Electromagnetic Radiation from Video Display Units: An Eavesdropping Risk?", Computers & Security 4 (4): 269-286, https://cryptome.org/emr.pdf  — "This paper describes the results of research into the possibility of 'eavesdropping' on video display units, by picking up and decoding the electromagnetic interference produced by this type of equipment. During the research project, which started in January, 1983, it became more and more clear that this type of information theft can be committed very easily using a normal TV receiver."
• Smulders, Peter (Feb. 1990), "The Threat of Information Theft by Reception of Electromagnetic Radiation From RS-232 Cables", Computers & Security 9 (1): 53-58  — "Electromagnetic radiation arising from RS-232 cables may contain information which is related to the original RS-232 data signals. The seriousness of eavesdropping risks is shown by estimates of bit error rates feasible with a standard radio receiver as a function of the separation distance. In addition to this, results of experimental eavesdropping are presented."