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Hardware Hacking Privacy Wireless Networking Build

Researchers Turn Home Wi-Fi Router Into Spy Device 108

Posted by Unknown Lamer
from the no-warrant-required dept.
hypnosec writes "Researchers at University College of London have applied principles of radar used in defense and designed a detector using home based Wi-Fi routers to spy on people across walls. Using the principles behind the Doppler effect ... Karl Woodbridge and Kevin Chetty, at University College London, have built a prototype unit that uses Wi-Fi signals and recognizes frequency changes to detect moving objects. The size of the prototype unit is more or less the size of a suitcase. The unit contains a radio receiver comprising of two antennas and a signal-processing unit. The duo carried out test runs and ... they managed to determine a person's location, speed, and direction (even through a one foot thick brick wall). The device could be used to spot intruders, monitor children or the elderly, and could even be used in military applications."
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Researchers Turn Home Wi-Fi Router Into Spy Device

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  • Re:Hats and shield (Score:3, Informative)

    by maxwell demon (590494) on Saturday August 04, 2012 @05:54AM (#40876527) Journal

    Well, just wait for the FUCK act (Facebook Update Complete Knowledge act). That will make it illegal to not put everything about yourself on Facebook.

  • Re:Wrong history... (Score:4, Informative)

    by cbiltcliffe (186293) on Saturday August 04, 2012 @06:31AM (#40876637) Homepage Journal

    So does that mean if I'm exploring out in the woods, and I stumble upon a cave entrance, that the cave didn't exist prior to my discovery?
    If I'm researching some technology and I stumble upon a related patent, that the patent didn't exist before I found it? Great, that means I just need to stumble across every patent in the USPTO, and I own every technology in existence!!

    Screw the rest of the steps, just:

    5. PROFIT!!!!1!

    Your interpretation is completely at odds with decades of history of this phrase.

  • Passive radar (Score:3, Informative)

    by Anonymous Coward on Saturday August 04, 2012 @06:43AM (#40876659)

    http://en.wikipedia.org/wiki/Passive_radar [wikipedia.org]

    Passive radar uses radio sources, like TV and FM stations, instead of having its own transmitter. The receiver detects the direct signal from the transmitter and the signal reflected from the target. The trick is to separate the two. Using the doppler effect does that nicely for moving targets.

    The advantage of passive radar is that it can't be detected.

    The radar in TFA doesn't need to be undetectable, the targets probably don't have detectors. It could have its own transmitter. That would simplify the receiver design a lot. The transmitter is quite simple and cheap, being a GUNN diode or something like that. It would also require a directional transmitting antenna. Developing such a device would be much cheaper and it would work much better.

    Given that the researchers did the job the hard way, their accomplishment is quite impressive. On the other hand, we haven't seen a fully field tested version. There is a large gap between a lab demo under controlled circumstances and an actual useable device.

  • Home Wi-Fi Router? (Score:5, Informative)

    by jones_supa (887896) on Saturday August 04, 2012 @06:47AM (#40876681)
    The headline is a bit misleading. They did not convert a Wifi station to a spy device, but created a completely separate device to interpret Wifi signals and their reflections in a building.

Always think of something new; this helps you forget your last rotten idea. -- Seth Frankel

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