Cross-Device tracking

[Morla]

So I read about Cross-device tracking and one of the methods used involves ultrasonic sound being emitted through TV and received by rogue android apps. I think this could be a reason to put a filter in place to remove everything >20khz?

 

[Philbo King]

Frankly, most users could cut everything above 10k. That last octave doesn't contribute much anyway, assuming you can hear it at all. To see for yourself, try cutting everything below 10k. Not much going on, usually.

 

[unpluggged]

I think this could be a reason to put a filter in place to remove everything >20khz?

Yes, here is an example of such a filter (must be connected to ground to work):

ultrasonic sound being emitted through TV

Emitted how?

and received by rogue android apps

Received how? And why not by rogue iOS apps?

On the scientific value of the paper the linked Wikipedia article is based on, all I can say is to quote this passage:

We create ultrasonic beacons that cover different frequencies, lengths and sound levels. In particular, we choose frequencies between 18 and 20 kHz

I think it says it all about the competence of its authors.

 

[Morla]

On the scientific value of the paper the linked Wikipedia

So you wanted to say it's not real at all? The actual paper from a german University

https://intellisec.de/pubs/2017a-eurosp.pdf

 

[Morla]

Yes, here is an example of such a filter (must be connected to ground to work):

View attachment 458067

That guy, eh?

 

[DVDdoug]

High frequency soundwaves don't travel very far and they tend to be directional so they don't go around corners. They certainly can't track you once you leave the room.

If you've been to an outdoor music event you may have noticed that as you get some distance away all you hear is the bass. Or if you hear your neighbor's stereo or the TV/Stereo from another room, it's "muffled" (loss of high frequencies) and you mostly hear the bass.

Of course, they'd have to trick you into installing malware on your phone.

 

[NTK]

The rogue apps will have to have access to the mic in the device, which means it can also eavesdrop on all conversations around it. Sounds to me a more serious security threat?

 

[Morla]

that malware function might come in disguise as an advertisment component/library for monetizing.On Android it would require users consent but probably easy to get if you want to use a "free" app. If irc the idea was having the tv sending stuff that an app can receive and then snitch to servers yes that guy looks at this ad in the tv. Also: whoever reads this: I am not feeling paranoid or anything for me this idea of tracking by connecting otherwise seperated devices was new to me. Like a sidechannel

 

[JeremyFife]

The paper is quite interesting actually ... not using ultrasonics, but higher generally inaudible frequencies. Reads like its worrying about something that is theoretically possible, rather than anything in the real world.

Should be easy to detect with REW and a umic

Agree with @NTK - I'd be far more worried about a rogue app taking over my mic than I am about this

 

[Salt]

That's all about acoustics, but we can step ahead to electromagnetic (thinking about combination ):
https://www.heise.de/en/news/Biomet...w-identification-and-monitoring-10515756.html

 

[Morla]

That's all about acoustics, but we can step ahead to electromagnetic (thinking about combination ):
https://www.heise.de/en/news/Biomet...w-identification-and-monitoring-10515756.html

Given that there are many provider controlled wifi routers it's concerning