< Back to previous page

Publication

Compromising Electromagnetic Radiation of Information Displays

Book - Dissertation

Information technology equipment (ITE) leak electromagnetic signals either by radiation or conduction. These emissions or emanations can be picked up and under certain conditions the information can be captured. In case of radiation leakage this means that even air gapped equipment can be spied upon. This makes it possible to gain access to sensitive or confidential information using unconventional methods. These methods are an attractive way to gain unauthorized access due to the fact that it is untraceable, no physical access is needed and that cryptographic protocols and authentication tokens are becoming more ubiquitous. Monitors which continuously display information are the most common targets for this eavesdropping threat. Compromising radiation is often called Tempest radiation in literature. Tempest is "a U.S. government code word that identifies a classified set of standards for limiting electric or electromagnetic radiation emanations from electronic equipment." But in literature, Tempest references mostly to a collection of methods and techniques that use these emanations for eavesdropping. Nevertheless, few of these methods are shared publically for strategic purposes. The most important contribution that are made in open literature are the works of Wim Van Eck (Electromagnetic Radiation from Video Display Units: An Eavesdropping Risk? (1985)) and from Markus G. Kuhn (Compromising emanations: eavesdropping risks of computer displays. (2003)). Wim Van Eck's work in 1985 was a real eye-opener when he reconstructed the image of a CRT with a basic electronic equipment with a distance of couple of meters. After Van Eck's work not many notable works were published until Markus G. Kuhn published a technical report about compromising emanations of computer displays. Kuhn's work continued on Van Eck's work and tried to shed some light on the exact mechanisms that result in these emanations and proofed that digital based systems also suffer from these unintended information leaks. Now almost 15 years later, Van Eck and Kuhn's works are still the most notable works that thoroughly investigated this matter but are now outdated and still left us with many questions. This PhD will investigate different areas of this specific threat to fully understand the working mechanisms, the proof of concept if this kind of eavesdropping is possible without any foreknowledge and to find effective countermeasures. A more detailed description of the PhD objectives is written in the next three bulletins: 1. The first objective is to characterize these emanations. Study, analyse and form new techniques that can detect, filter and manipulate emanations of information displays. This opens up the possibility to fully understand the emanation sources, spectrum and the dependency on environment variables. 2. The second objective is the proof of concept that a displayed image can be reconstructed from the emanations without foreknowledge of the information display. In other words design and devise a functional eavesdropping system that can detect the information displayed on a screen using solely the information in the emanation itself. 3. The third objective is to investigate effective countermeasures and protection against this specific threat. Modelling the emanations of a monitor with its specific characteristics and be able to simulate these emanations at specific distances will open up the possibility to effectively find protection techniques against this sort of eavesdropping. For instance to determine only from the specification of a system which information system performs better against this eavesdropping threat compared to others.
Publication year:2021
Accessibility:Open