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Bluetooth signals can be used to identify and track smartphones

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Re: Bluetooth signals can be used to identify and track smartphones

#41

Post by pmoriarty »

_carbyau_ wrote: post #36
neuralRiot wrote: post #9

Earlier quoted context omitted.

Faraday bags

Fortunately, convenient and cheap with tasty contents! https://arstechnica.com/information-technology/2017/11/austr...

According to that article, it looks like the bags have to be grounded to work:

"Snack packets are made with a foil that combines aluminum and mylar plastic, making them electrically conductive and ideal as a temporary electromagnetic shield for mobile devices—as long as the packet is closed and grounded—and you don't mind a few crumbs on your device."

I'm not sure if that's really true, or why that is... and if it is, how one could do it while on the move.

Re: Bluetooth signals can be used to identify and track smartphones

#42

Post by _carbyau_ »

pmoriarty wrote: post #41
_carbyau_ wrote: post #36

Earlier quoted context omitted.

Fortunately, convenient and cheap with tasty contents! https://arstechnica.com/information-technology/2017/11/austr...

According to that article, it looks like the bags have to be grounded to work: "Snack packets are made with a foil that combines aluminum and mylar plastic, making them electrically conductive and ideal as a temporary electromagnetic shield for mobile devices—as long as the packet is closed and grounded—and you don't mind a few crumbs on your device." I'm not sure if that's really true, or why that is... and if it is…

Yeah, my understanding of the faraday cage property is that it equalizes the charge across the surface.

Whether that charge is equal to ground or not is irrelevant I thought.

I will make the sacrifice tonight and eat a packet of chips for testing I guess. It is a hard life.

Re: Bluetooth signals can be used to identify and track smartphones

#45

Post by olliej »

notorandit wrote: post #17

Do you mean that you ignore the unique BT MAC address and track instead those tiny signal deviations that hopefully make each device unique? Cool!

I think all Apple devices at this point randomly change the MAC for both Wi-Fi and BT, and have done for a few years at least. Specifically to prevent that tracking.

Targeting variation in the signal itsel (rather than the content) seems on its face to be much harder to prevent. But I am not a radio (or any electrical) engineer so what do I know? :)

Re: Bluetooth signals can be used to identify and track smartphones

#46

Post by olliej »

cvccvroomvroom wrote: post #20

This is generally old news. Philz Coffee in Palo Alto, CA and major department stores in the US have been doing this for years to track foot traffic. If you don't want to be tracked, turn off BT and Wifi and demand the protocol stds body and mfgrs support even stronger randomized hw addresses.

Which is why modern secure devices randomly cycle Wi-Fi and Bluetooth MACs fairly frequently.

Re: Bluetooth signals can be used to identify and track smartphones

#47

Post by superkuh »

If your phone is transmitting radio signals it is identifiable and trackable. A smart phones' primary feature and defining feature is transmitting radio signals. I don't think anyone is surprised at these "anonymous" bluetooth functions being deanonymized. But at least bluetooth beacons aren't going to go very far.

Multi-lateration of cell phone radio transmission via precise shared clocks at the base stations gives telcos a ~100m (these days) position that is updated very frequently. In the USA this stored by telcos for 2-5 years and is often sold to both private and government purchasers.

And anyone moderately skilled in SDR with a few thousand dollars can do the same for a small area (much larger than a bluetooth area though).

Re: Bluetooth signals can be used to identify and track smartphones

#48

Post by bragr »

pmoriarty wrote: post #27

In another hundred years are people going to look back at this time as a barbaric age of surveillance or are they going to be even more surveilled and controlled than ever before? So far the trend is towards the latter...

I think it will be a mix. There's always been the use of technology to both enhance and break privacy. On one hand you have surveillance, on the other you have encryption. It is a give and take and the march of progress will always render previous methods inadequate. Hundreds of years ago, letter locking was the thing for secure, private communication, but now we can read those letters without even opening them.

http://letterlocking.org/imaging-locked-letter-collections

Re: Bluetooth signals can be used to identify and track smartphones

#49

Post by lobocinza »

pmoriarty wrote: post #41
_carbyau_ wrote: post #36

Earlier quoted context omitted.

Fortunately, convenient and cheap with tasty contents! https://arstechnica.com/information-technology/2017/11/austr...

According to that article, it looks like the bags have to be grounded to work: "Snack packets are made with a foil that combines aluminum and mylar plastic, making them electrically conductive and ideal as a temporary electromagnetic shield for mobile devices—as long as the packet is closed and grounded—and you don't mind a few crumbs on your device." I'm not sure if that's really true, or why that is... and if it is…

If it's not grounded charge will accumulate on the exterior walls but I doubt it will be significant for a cellphone.

Re: Bluetooth signals can be used to identify and track smartphones

#50

Post by godelski »

How is this "for the first time?" I saw a well established company demonstrating this technology 5 years ago. They were selling it on being able to either track your employees (this was gov fwiw) or other people in your building. They could do it both through WiFi and Bluetooth and uniquely identify you. While I think this technology is concerning, I'm confused what's new here and trying to read through the marketing.
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