[et-al]

Layman question: one can limit their exposure with encrypted VoIP communications (e.g. FaceTime) and chats (iMessage, Signal), correct?

That being said, the intercepter would still know:

- phone being connected (IMEI)

- location of the phone

- which servers were requested, but not the encrypted content (yet)

- how much data was transmitted, "call time"

So if two phones were talking with each other over FaceTime connected to stingrays, a third-party can still deduce that they were talking to each other given the amount of data being transferred and when the requests occurred.

[walrus01]

Re: your last sentence, a stingray rarely if ever offers actual network connectivity, either ss7 or data. Its purpose is just to catch the unique ID numbers from the phone. Whatever you have set into your phone for LTE APN data settings isn't going to work with a random imsi catcher. Such a thing won't have an uplink anyways outside of its command/control functions.

[gruez]

Doesn't that make them really detectable? A deadspot with full signal bars would be really suspicious.

[walrus01]

A phone doesn't stay connected to a stingray, it will get the imsi and then move on to a real site of the phone's carrier.

[pas]

How/why? Could you elaborate? Will the rouge tower drop the phone? Won't the phone try to connect again and again to the tower with the strongest signal?

[et-al]

Thanks! Didn't know that about stingrays.

[cryptonector]

The metadata is most of the story. Certainly, if the stingray lets arbitrary protocols through, you can secure the contents of your communications, including any metadata tunneled through (e.g., if you're using VPN), but not the metadata on the outside of the tunnel. Depending on the VoIP protocol, you may not get any protection for metadata unless you're using a VPN.