Links and Other Materials
Optical (LED) Information Leakage
Security Now! listener, Evan Powers, has a terrific memory. He found and supplied links to the original research conducted by Joe Loughry of Lockheed Martin Space Systems and David Umphress of Auburn University:
From the authors’ introductory abstract:
A previously unknown form of compromising emanations has been discovered. LED status indicators on data communications equipment, under certain conditions, are shown to carry a modulated optical signal that is significantly correlated with information being processed by the device. Physical access is not required; the attacker gains access to all data going through the device, including plaintext in the case of encryption systems. Experiments show that it is possible to intercept data under realistic conditions at a considerable distance. Many different sorts of devices, including modems and Internet Protocol routers, were found to be vulnerable. [. . .]
This is a preprint of their complete paper to appear in the Proceedings of the 12th ACM Conference on Computer and Communications Security, November 2005.
This is the official keyboard emanations web site referred to as the end of their ACM preprint paper which will eventually contain the prototype code, in Matlab and Java, of the keyboard emanation sound “attack” and their data sets.
This page on the Federation of American Scientists web site describes “TEMPEST” and provides additional background and terminology about surveillance technology associated with electromagnetic emissions and emanations from electronic equipment.
The Law Surrounding Emanation Interception
As you can see from this page, it appears that since the sound of keyboard typing is not INTENDED as communication, its interception and use AS communication is not covered by any prevailing laws in the United States, England, or Canada, and is therefore not unlawful.
Links to news coverage of the Zhuang/Zhou/Tygar ACM research:
This is UC Berkeley’s official press release: “Researchers recover typed text using audio recording of keystrokes”.
This page ends with a series of forum-style comments that you might find interesting and useful.
Reprint of Dan Fost’s article in the San Francisco Chronicle
IDG News Service coverage of the story
(source: Mechanical & Electromagnetic Information Leakage)