Date: Wed, 14 Apr 2004 18:08:20 -0700 From: richard childers / kg6hac <fscked@pacbell.net> To: Wilko Bulte <wkb@freebie.xs4all.nl> Cc: freebsd-mobile@freebsd.org Subject: Re: Hams Report 85-mile 802.11b File Transfers @ Oregon Message-ID: <407DE084.5000104@pacbell.net> In-Reply-To: <20040414202039.GA1217@freebie.xs4all.nl> References: <407D7323.50001@pacbell.net> <04041413050408.02105@sandino.dnsalias.org> <20040414202039.GA1217@freebie.xs4all.nl>
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Wilko Bulte wrote: "What counts that Mr Evil Eavesdropper can get listening access to your AP well away from your location." Put another way, the area equals pi times the radius, squared ... so the number of people who have the theoretical opportunity to passively crack your wireless network increases, dramatically, with each increment of distance from the center. You can pack an awful lot of people into a circle with a radius of 85 miles ... that's 170 miles, diametrically. (I am reminded of the Summer, 2002 release of _2600, the Hacker Quarterly_, where a geospatial diagram of all wireless networks, their estimated locations, estimated field strengths, and encryption (or lack thereof) was displayed on the front cover, as a series of overlapping red (and green) circles, overlaid on a map of Manhattan ... with a little effort, now, it's not unlikely that the guys in the W1AW shack, at the ARRL HQ, in Newington, Connecticut, can pick up the transmissions from Manhattan, too ... along with everyone else, in between. Heh! Marconi would be amused, I hope.) This led to the conception of a whole new distributed networking application; cracking wireless networks by distributing the data across multiple CPUs and working on cracking the key by dividing the search space into smaller pieces that could be searched in parellel. It's only a matter of time. Regards, -- richard >On Wed, Apr 14, 2004 at 01:05:04PM -0700, Scott Weikart wrote: > > >Well, I recently tried an old 25" satellite dish and a biquad feeder >and we easily 'saw' APs at 3-4 miles away. Without trying anything fancy. >You need line of sight to the AP in most cases. Hills help. > > >>I would assume the hams used directional antennas on both ends, and >>carefully pointed the antennas at each other. >> >>So, this may have little relevance to monitoring people's >>mostly-omnidirectional wireless LANs. Well, maybe you could so some >>math to make the ham's numbers scale, but I would guess there are >>more direct methods to measure/compute risk. >> >>-scott >> >> >> >> -- Richard Childers / Senior Engineer Daemonized Networking Services 945 Taraval Street, #105 San Francisco, CA 94116 USA [011.]1.415.759.5571 http://www.daemonized.com
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