Van Eck phreaking

Source: Wikipedia, the free encyclopedia.

Van Eck phreaking, also known as Van Eck radiation, is a form of

electromagnetic emissions of electronic devices. While electromagnetic emissions are present in keyboards, printers, and other electronic devices, the most notable use of Van Eck phreaking is in reproducing the contents of a cathode-ray tube
(CRT) display at a distance.

Information that drives a CRT

synchronization pulses
are recreated and mixed in, an ordinary analog television receiver can display the result. These emissions are correlated to the video image being displayed, so, in theory, they can be used to recover the displayed image.

While the phenomenon had been known by the United States Government and Bell Labs as early as the Second World War, the process received its name after Wim van Eck published the first unclassified technical analysis of the security risks of emanations from computer monitors in 1985. While phreaking is the process of exploiting telephone networks, the term is used here because of its connection to eavesdropping.

History

Government researchers were already aware of the danger, as Bell Labs had noted this vulnerability to secure teleprinter communications during World War II and was able to produce 75% of the plaintext being processed in a secure facility from a distance of 80 feet (24 metres).[1] Additionally, the NSA published Tempest Fundamentals, NSA-82-89, NACSIM 5000, National Security Agency (Classified) on February 1, 1982. Also, the van Eck technique was successfully demonstrated to non-TEMPEST personnel in Korea during the Korean War in the 1950s.

In 1985,

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 the paper, Van Eck reports that in February 1985, a successful test of this concept was carried out with the cooperation of the

antenna array, they were able to eavesdrop from a "large distance". There is no evidence that the BBC's TV detector vans used this technology, although the BBC will not reveal whether or not they are a hoax.[4]

Van Eck phreaking and protecting a CRT display from it was demonstrated on an episode of Tech TV's The Screen Savers on December 18, 2003.[5][6]

Basic principle

Information that drives the

radio emissions are correlated to the video
image being displayed, so, in theory, they can be used to recover the displayed image.

In a CRT, the image is generated by an

synchronization pulses are recreated and mixed in, an ordinary analog television receiver can display the result. The synchronization pulses can be recreated either through manual adjustment or by processing the signals emitted by electromagnetic coils as they deflect the CRT's electron beam back and forth.[3]

Use as communication

In January 2015, the Airhopper project from

Ben Gurion University, Israel) the use of Van Eck Phreaking to enable a keylogger to communicate, through video signal manipulation, keys pressed on the keyboard of a standard PC, to a program running on an Android cellphone with an earbud radio antenna.[7][8][9]

Equipment

A tailored access battery is a special laptop battery with Van Eck Phreaking electronics and power-side band encryption cracking electronics built into its casing, in combination with a remote transceiver. This allows for quick installation and removal of a spying device by simply swapping the battery.[10]

Potential risks

Van Eck phreaking might be used to compromise the secrecy of the votes in an election using

2006 national elections, under the belief that ballot information might not be kept secret.[11][12] In a 2009 test of electronic voting systems in Brazil, Van Eck phreaking was used to successfully compromise ballot secrecy as a proof of concept.[13]

Further research

In April 2004, academic research revealed that flat panel and laptop displays are also vulnerable to electromagnetic eavesdropping. The required equipment for espionage was constructed in a university lab for less than US$2000.[14]

least significant bits of pixel values may render the emanations from flat-panel displays unintelligible to eavesdroppers but is not a secure method. Since DVI uses a certain bit code scheme that tries to transport a balanced signal of 0 bits and 1 bits, there may not be much difference between two pixel colors that differ very much in their color or intensity. The emanations can differ drastically even if only the last bit of a pixel's color is changed. The signal received by the eavesdropper also depends on the frequency where the emanations are detected. The signal can be received on many frequencies at once and each frequency's signal differs in contrast and brightness related to a certain color on the screen. Usually, the technique of smothering the RED signal with noise is not effective unless the power of the noise is sufficient to drive the eavesdropper's receiver into saturation
thus overwhelming the receiver input.

See also

References

  1. ^ "A History of U.S. Communications Security (Volumes I and II)"; David G. Boak Lectures" (PDF). National Security Agency. 1973. p. 90.
  2. ^ Greenberg, Andy (21 June 2020). "Hacker Lexicon: What Is a Side Channel Attack?". Wired.
  3. ^
    doi:10.1016/0167-4048(85)90046-X
    .
  4. ^ Carter, Claire (27 September 2013). "Myth of the TV detector van?". The Daily Telegraph. Retrieved 27 September 2015.
  5. ^ Van Eck Phreaking
  6. ^ The Screen Savers: Dark Tip – Van Eck Phreaking
  7. ^ Air-gapped computers are no longer secure, TechRepublic, January 26, 2015
  8. ^ Original Whitepaper
  9. ^ Airhopper demonstration video, Ben Gurion University
  10. ^ White paper, FDES institute, 1996, page 12.
  11. ^ Dutch government scraps plans to use voting computers in 35 cities including Amsterdam (Herald tribune, 30. October 2006)
  12. ^ Use of SDU voting computers banned during Dutch general elections Archived 2008-09-23 at the Wayback Machine (Heise, October 31. 2006)
  13. ^ "Brazilian Breaks Secrecy of Brazil's E-Voting Machines With Van Eck Phreaking". Slashdot. November 21, 2009.
  14. ^ Kuhn, M.G. (2004). "Electromagnetic Eavesdropping Risks of Flat-Panel Displays" (PDF). 4th Workshop on Privacy Enhancing Technologies: 23–25.
  15. ISSN 1476-2986
    . UCAM-CL-TR-577. Retrieved 2010-10-29.
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