5 ms·

“There are a ton of devices jumping into that space and communicating there,” he says. “It’s not feasible to say ‘we’ll chase down everyone who has this device

by madengr 11y ago

“There are a ton of devices jumping into that space and communicating there,” he says. “It’s not feasible to say ‘we’ll chase down everyone who has this device communicating on this frequency.’ It’s a needle in a haystack.” That's a load of BS. Guy is very naive. http://literature.cdn.keysight.com/litweb/pdf/5989-9207EN.pdf?id=1708535 http://literature.cdn.keysight.com/litweb/pdf/5989-9207EN.pd... You just need three of these to TDOA a single burst. http://www.keysight.com/en/pd-1414739-pn-N6841A/rf-sensor?nid=-34395.804598&cc=US&lc=eng http://www.keysight.com/en/pd-1414739-pn-N6841A/rf-sensor?ni...

pavel_lishin 11y ago
If I'm understanding your comment, you're saying that it would be easy to detect the person with the antenna by doing some triangulation. But this would still require authorities on the ground, and aware that you're using a setup such as this. This isn't a silver bullet, it's just another layer of protection.
nathan_f77 11y ago
That's a really good point. So you would definitely stop using the device as soon as you know it's compromised. I like the idea of using an accelerometer and a light sensor to trigger a warning which immediately turns off both radios. But that's really easy to avoid. If they trace the IP to a Starbucks, then it's very easy to find the location of the wifi client. If it's under a table or in a wall, then don't touch it. Just take over the AP and start watching all the traffic. Then scan for RF, correlate network activity with RF bursts, triangulate. And now I'm thinking about how you might be able to defeat triangulation... Maybe a cluster of radios, some public key crypto... decentralized frequency modulation? I wonder if you could do some tricky stuff with frequency modulation if you know precise distances between the transmitters and receiver, and account for variable weather conditions, etc. Somehow build a cloud of radio waves that evenly covers an area within a given radius, and the receiver knows how to decode data which was sent by the real transmitter. And each transmitter is continuously sending random data, so it's impossible to determine if one of the transmitters is a decoy, or the real one. No, I don't think this would work. I'm sure it would be easy to triangulate each individual transmitter, and then just capture all positions at once. I love thinking about this stuff, though. What other ideas are there? Maybe if you owned the Starbucks itself, then you could do some tricky stuff with NAT to try and confuse the agents. EDIT: Another idea: What if you use a quadcopter as a relay between different radio frequencies, and make it fly around in random patterns... You could have a buffer of packets that empties at random intervals, so you couldn't link the radio bursts together. I just got my Flutter board [1] a few weeks ago, might be a fun experiment. [1] https://www.kickstarter.com/projects/flutterwireless/flutter-20-wireless-arduino-with-half-mile-1km-ran https://www.kickstarter.com/projects/flutterwireless/flutter...

by madengr 11y ago

pavel_lishin 11y ago

If I'm understanding your comment, you're saying that it would be easy to detect the person with the antenna by doing some triangulation. But this would still require authorities on the ground, and aware that you're using a setup such as this. This isn't a silver bullet, it's just another layer of protection.

nathan_f77 11y ago

That's a really good point. So you would definitely stop using the device as soon as you know it's compromised. I like the idea of using an accelerometer and a light sensor to trigger a warning which immediately turns off both radios. But that's really easy to avoid. If they trace the IP to a Starbucks, then it's very easy to find the location of the wifi client. If it's under a table or in a wall, then don't touch it. Just take over the AP and start watching all the traffic. Then scan for RF, correlate network activity with RF bursts, triangulate. And now I'm thinking about how you might be able to defeat triangulation... Maybe a cluster of radios, some public key crypto... decentralized frequency modulation? I wonder if you could do some tricky stuff with frequency modulation if you know precise distances between the transmitters and receiver, and account for variable weather conditions, etc. Somehow build a cloud of radio waves that evenly covers an area within a given radius, and the receiver knows how to decode data which was sent by the real transmitter. And each transmitter is continuously sending random data, so it's impossible to determine if one of the transmitters is a decoy, or the real one. No, I don't think this would work. I'm sure it would be easy to triangulate each individual transmitter, and then just capture all positions at once. I love thinking about this stuff, though. What other ideas are there? Maybe if you owned the Starbucks itself, then you could do some tricky stuff with NAT to try and confuse the agents. EDIT: Another idea: What if you use a quadcopter as a relay between different radio frequencies, and make it fly around in random patterns... You could have a buffer of packets that empties at random intervals, so you couldn't link the radio bursts together. I just got my Flutter board [1] a few weeks ago, might be a fun experiment. [1] https://www.kickstarter.com/projects/flutterwireless/flutter-20-wireless-arduino-with-half-mile-1km-ran https://www.kickstarter.com/projects/flutterwireless/flutter...