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Comment by rhizome | Hacker News Reader

Who is going to be the first device manufacturer to provide Stingray protection for their phones? Apple? Google?

It's in the chipset of the cellular radio (3G/4G/etc), whose source is generally not available to anyone. And, more to the point, the code running on the chip can deceive the operating system.

Apparently there's an undocumented iOS API to let apps get some cellular base station data (though on iOS it additionally requires jailbreaking; I'm not sure if that's an app privilege issue or just an "Apple banning software that uses undocumented APIs from the App Store" issue).

http://signal.kssh.ca/

Current IMSI catcher devices aren't routinely attacking the baseband, so many of their targets could probably detect them with judicious use of these APIs.

Perhaps more to the point, there is an "IMSI catcher catcher" project based on Osmocom-BB:

https://opensource.srlabs.de/projects/mobile-network-assessm...

The downside is that you need a handset that can run Osmocom (almost certainly not the case for your current handset). The upside is that you can actually get plausibly credible data about the GSM base stations around you, including data that might reveal if some of them are fake.

... maybe there's a documented Android API for a subset of this information?

http://signalmonitoring.com/en/gsm-field-test

Well, iOS does offer a hidden Field Test app that can surface a subset of this cellular base station data.

The code is * 3001#12345#* [1]. Tested on an iPhone 5S running iOS 7.1.1 that is not jailbroken.

[1] http://www.cultofmac.com/128306/access-the-hidden-field-test...

Interesting! I'd imagine that the data from this app might identify some kinds of IMSI catchers, depending on how they're configured and how well the user knows what to expect in their local GSM environment.

It looks and acts like a normal cell phone tower... so there is no good way to provide protection against it.

Stingray apparently works by overloading signal over an area. I'm sure some math comparing device motion with sudden-tower-appearance could be put together into a reasonable heuristic.

Stingray works by having a stronger signal (It's closer to the user, kind of like a wifi hotspot). This can happen at anytime anyway, carriers have put up mobile towers before so that they can take down a single or multiple towers in an area for maintenance, or to provide extra coverage.

Are there possible ways to detect it, possibly, but will there be a HUGE amount of false positives, I fear there will be.

My solution was only with 10 seconds of thought from a layman. I'm not even an Electrical Engineer. I'm guessing the best-of-the-best in the Google-rola and Apple-A7+ hives are capable of deeper thoughts on the issue. They're at least closer to the point of contact from the tower than I am.

That's pretty scary. That implies that in addition to the target, anyone in the general vicinity of the target ( up to whatever the range of these things are ) would be tracked as well.

It's a good thing we can trust our agencies not to keep databases containing this unrelated but invasive information....right?

That is indeed correct, anyone within the vicinity would also connect to the tower...

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