TEMPEST

TEMPEST is a U.S. government code word for a set of standards for limiting electric or electromagnetic radiation emanations from electronic equipment such as microchips, monitors, or printers. It is a counter-intelligence measure aimed at the prevention of electronic espionage. The term TEMPEST is often used more broadly for the entire field of compromising emanations or Emissions Security (EMSEC).

Public research

In 1985, Wim van Eck published the first unclassified technical analysis of the security risks of emanations from computer monitors. This paper caused some consternation in the security community, which had previously believed that such monitoring was a highly sophisticated attack available only to governments; van Eck successfully eavesdropped on a real system, at a range of hundreds of metres, using just $15 worth of equipment plus a television set. In consequence of this research such emanations are sometimes called "van Eck radiation", and the eavesdropping technique "van Eck phreaking", although it is realised that an unknown government researcher had discovered it long before. This technique is used as a plot point in Neal Stephenson's novel Cryptonomicon.

Related Topics:
1985 - Wim van Eck - Metre - Television - Van Eck phreaking - Neal Stephenson - Cryptonomicon

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Markus Kuhn discovered several low-cost software techniques for reducing the chances that emanations from computer displays can be monitored remotely. With CRT displays and analogue video cables, filtering out high-frequency components from fonts before rendering them on a computer screen will attenuate the energy at which text characters are broadcast. With modern flat-panel displays, the high-speed digital serial interface (DVI) cables from the graphics controller are a main source of compromising emanations. Adding random noise to the less significant bits of pixel values can render the emanations from flat-panel displays unintelligible to eavesdroppers.

Related Topics:
Markus Kuhn - CRT - Fonts - DVI

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