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Wardriving is the latest game computer hackers like to play. They drive around with an active WiFi (802.11 wireless LAN) device looking for wireless network connections they can tap into. This has become a huge potential security problem for corporations. One can use a firewall to prevent hackers
from entering their network over network wires, but how does one firewall off something that travels through the air?
There are cryptographic methods to secure WiFi connections, including the original WEP (Wired Equivalent Privacy) and the new WPA (Wireless Protected Access). But even these are not foolproof; ways have been discovered to hack both of them given enough time. And what if someone goofs up and doesn’t enable them?
Let us learn from the military here. Many military vehicles use “Electronic Counter Measures” (ECM) to jam or interfere with RADAR and other electronic systems of the enemy. Let’s do the same thing to wardrivers.
Mount a series of antennas on the outside surface of your office building. They are designed to transmit a highly directional signal away from the building. This signal fills up the 2.4 Ghz frequencies that WiFi uses with useless gobbledygook with enough power to overwhelm anything coming from the access points inside the building. Wardrivers will be unable to connect to anything due to the overwhelming ECM signal.
The band used by WiFi is unlicensed spectrum, so there is no restriction on how you choose to use it on your own property, as long as you don’t transmit a signal above a certain power level.
It is really only suitable for use in a campus-style environment where your building is well away from your neighbors, or else your ECM will jam the company next door too.
wardriving.com
http://www.wardriving.com/about.php
[krelnik, Oct 04 2004, last modified Oct 05 2004]
[link]
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is jamming your competitions wi-fi really so bad? |
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//useless gobbledygook//
Make it spam instead, and you've got a hot new product! Let people log into your jamming signal, but make every connection point to your advertisments. Sell ad space, too. The wardrivers connect to a server that is not part of the internet, but they'll see a lot of your ads before they figure it out.
OK, it's still useless gobbledygook, but you get paid to send it. |
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Actually some spammers are using wardriving techniques to send spam using corporate email servers. |
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there must be a better way... you are suggesting using a nuclear weapon for fishing border patrolling.. |
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Judging by the record of the military, workers in an office would most likely have more to fear from 'friendly fire' jamming than the hackers themselves. You could always just leave an old unix box attached to your network, containing pictures of naked women and vouchers for pizza and coke to lure the hackers away from your main I.T. infrastructure, much as bees will be attracted to an open jar of jam rather than your meal. |
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Well, that brings up another use for this too, which is for companies that have chosen to ban WiFi equipment on the premises. To prevent someone from bringing their own access point and hooking it up, aim the antennas into the building instead of away to deliberately jam everything. (The problem with that is Bluetooth lives in the same frequency band, so you'd probably disable all those devices too). |
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Or as a last resort, a wardriving EMP. |
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Is there a form of Faraday's cage that blocks EM, rather than electrostatic, fields? |
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How about this: Instead of transmitting jibberish it has a receive antenna pointed inward, and a transmit antenna pointed outward. Then it could try to do the RF equivalent of "noise cancellation" on the signal that leaks through the walls. (i.e. Transmit a signal precisely out of phase with the existing one, to cancel it out). Would probably be very difficult to get right if you had more than one access point. |
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// Is there a form of Faraday's cage that blocks EM, rather than electrostatic, fields? // [friendlyfire] |
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You could encase the room in construction grade Mu metal. Mu metal is a generic term covering a number of high permeability nickel-iron alloys. EM shielding is accomplished by diverting magnetic flux along the length of the alloy, thereby preventing EMI from passing through its thickness. It is commonly used to prevent EMI from affecting sensitive electronic circuits. The stuff is hideously expensive so enclosing an entire room would not be practical for most, though I understand it is sometimes done. |
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// The band used by WiFi is unlicensed spectrum, // |
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The band used by WiFi is is shared with licensed services. The lower 6 802.11b channel are shared with the 2.4Ghz ham band, and the upper channels are shared with ISM (I think its called ISM). |
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