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Wi-Fi Sniffing Lets Researchers Build Graph of Offline Social Networks

Posted by Unknown on from the think-before-you-connect dept.

angry tapir writes "The probe requests emitted by a smartphone as it seeks a Wi-Fi network to connect reveal the device's manufacturer thanks to its MAC address. This can offer some information about a crowd of people by looking at the breakdown by device brand. However, because some OSes include a preferred network list (PNL) in their probes, it may be possible to use Wi-Fi sniffing to infer even more information about a group of people by looking for common SSIDs, and potentially mapping them to known network locations (PDF). A group of Italian researchers has been looking at ways to use the information in probe requests to analyze the social connections of crowds." The idea being that if you share preferred networks (especially ones only seen infrequently) you are more likely to be socially connected.

4 of 38 comments (clear)

  1. Illegal by Solandri · · Score: 3, Informative

    Didn't you get the memo? The courts think sniffing open wifi networks is a violation of wiretap laws.

  2. snoopin in places I didn't know I had places by Iamthecheese · · Score: 3, Funny

    These scurvy snoops be too interested in things that don't concern them. Must I hide not only me mac, computer name, browser type, and personal information but local network addresses as well? I'm really tired o' puttin' up new curtains. Me treasure maps will be well hid no matter how I have to do it but I'm wanting to put me wooden leg up some CEO asses.

    --
    If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
  3. Another example of data "leakage" by WuphonsReach · · Score: 3, Insightful

    Eh, the better question is "why does your computer leak data other then the MAC address"? Which is exactly what the PNL (preferred network list) is doing.

    Sure, it might save battery life, but information leakage like that should be off by default.

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    Wolde you bothe eate your cake, and have your cake?
    1. Re:Another example of data "leakage" by jrumney · · Score: 3, Informative

      Because some people configure their access points to not broadcast the SSID in the misguided belief that they can add a layer of security by doing that, devices will actively try to connect to networks that they cannot see. So anyone anywhere can see your device periodically trying to connect to every network that it is configured to connect to automatically. This doesn't save battery life, if anything it uses more than sitting passively listening for known networks would, but the idiocy of hidden SSIDs is widespread enough that it is necessary for WiFi to just work for mobile devices.