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Americans’ Cellphones Targeted in Secret U.S. Spy Program

online.wsj.com

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Re: Americans’ Cellphones Targeted in Secret U.S. Spy Program

#31

Post by lawnchair_larry »

jacquesm wrote: post #29
adventured wrote: post #23

Earlier quoted context omitted.

That's incorrect. It's illegal for you to do something like this. Very illegal. They would likely arrest you for attempting to purchase one, even if you had done nothing wrong. You could try to sue them, but then you can do that at any time; trying is never the problem, the consequences are. It's not a situation where they were granted permission to do it, in a Constitutionally friendly sort of way. These are extra-l…

Why is receiving data openly transmitted on the airwaves illegal?

These aren't passive devices. They have to "stomp" on AT&T's signal to get your phone to associate with them, then spoof as the carrier.

There is a loophole though - if you target a phone with the correct bands, one of the european bands is a ham radio band in the US, so licensed operators can play around that way.

Also, the DIY version is about $1000.

Re: Americans’ Cellphones Targeted in Secret U.S. Spy Program

#34

Post by r0h1n »

Thinking aloud in terms of a "solution" - is it possible to build crowdsourced blocklists that can be subscribed to by users, and will refuse to let their phones connect to "fake" celltowers?

P.S. I'm not a wireless guy, so I don't know if there's any kind of a digital giveaway that can distinguish a fake cell tower versus the real one it is spoofing. If there isn't, then perhaps the fault lies with existing wireless comm. standards.

Re: Americans’ Cellphones Targeted in Secret U.S. Spy Program

#36

Post by mindslight »

droopybuns wrote: post #27
mindslight wrote: post #20

Earlier quoted context omitted.

The application OS is basically irrelevant when talking about cell communications. They'd have to design their own boards to even have a chance at isolating the "baseband" processor - to say nothing of controlling its behavior, especially as carriers want to keep its workings secret for "security" Most phones (anything CDMA, or most everything LTE) use a Qualcomm SOC, with both the baseband and application processor…

Can you provide some technical documentation that supports your assertion that the baseband and the application processor are sharing memory space? I thought they use different processors that are supporting essentially independent operating systems.

They're independent operating environments, but that doesn't mean their memories are isolated.

It's commonly accepted that most mobile SoCs operate this way. See the diagram/text on page 2 of https://www.usenix.org/system/files/conference/woot12/woot12... . To the extent that a specific Qualcomm processor might avoid such a design, it's impossible to know due to their longstanding culture of security through obscurity.

AFAIK, the Raspberry Pi is setup the same way, with the black box GPU being the master of the CPU that is commonly used to run Linux. This setup is only less problematic because the GPU lacks an unobservable network link.

Even the i9100, with an independent modem, was found to be setup with shared memory for communication - http://redmine.replicant.us/projects/replicant/wiki/GalaxySI...

Models like the Samsung i9300 have the modem chipset as an independent unit, although I've seen a block diagram indicating that the eMMC flash and modem RAM are in the same package, which is worrying.

Re: Americans’ Cellphones Targeted in Secret U.S. Spy Program

#39

Post by ck2 »

This makes me wonder if the government has or is working on drones that hone in on a specific cellphone signal with a specific id after being trained.

Not just for tracking but an "icbm" kind of drone. First for military use, then for domestic use like how the police always get military weapon, iris scanners, etc.

Re: Americans’ Cellphones Targeted in Secret U.S. Spy Program

#40

Post by kordless »

navyrain wrote: post #16
declan wrote: post #7

Here are some excerpts from the WSJ paywalled article: Cellphones are programmed to connect automatically to the strongest cell tower signal. The device being used by the U.S. Marshals Service identifies itself as having the closest, strongest signal, even though it doesn’t, and forces all the phones that can detect its signal to send in their unique registration information. Even having encryption on one’s phone, su…

In addition to the egrigious complaints citizens could make, wouldn't telecoms and cellphone manufacturers have grounds to sue over this? It sounds like these boxes are actively disrupting or reducing cell-phone service reliability by tricking devices to connect to them, despite not being a good tower.

IIRC, most phones will talk to multiple towers at the same time. They mention attempting to keep disruption to a minimum. One would assume they care about not tipping someone off if their phone was acting funny.
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