• General

  • Can anything shield IMSI from IMSI catchers?

K8y

K8y thank you, so if I go to a protest with this setup and find a hotspot, stingrays would not see my SIM or IMSI numbers while I chat on Signal or Session?

This is an interesting conversation, with a lot of history. To add, here are some links that may answer questions about IMSI catchers, etc. in general:

Plain language technical information about IMSI catchers: https://www.eff.org/wp/gotta-catch-em-all-understanding-how-imsi-catchers-exploit-cell-networks

If you're generally interested in protest security - this 'Surveillance Self Defense' guide is pretty good and has a section on attending a protest: https://ssd.eff.org/

It's not just IMSI catchers though... Device/Person correlation can be derived from: AGPS location privilege given to an app that sells this data (e.g. Google fulfilling geo-fence warrants) or connecting to your University's Library Wi-Fi (e.g. Pamona College, etc. recently)...

        K8y There are, but they in turn would need a sim card to connect to a cellular tower. U got the point i guess, unless u can obtain a sim card that in no way can be linked to your real identity, and preferably buy the portable router cash, so imei can't be linked to u, might be an option then.

        • K8y likes this.

          Hill_Sphere I've just read the article linked, and came across an interesting observation.
          I'll quote the bit that i found interesting (Section 3.2.3)

          Section 3.2.3: Why aren’t users alerted that encryption is off?

          At this point, many people ask: why doesn’t their phone tell them something’s up? According to the GSM specifications, cell phone users are supposed to be notified when encryption is disabled, and in some markets they used to be. However, this caused a lot of confusion because:

          People would travel with their phones to places where cell towers were configured very differently (e.g. in some countries cell network encryption is banned) and it would cause a “Warning: encryption disabled” pop-up to come up a lot.
          Cell towers everywhere were misconfigured, also causing this pop-up to appear a lot.

          These issues led to many confused consumers and support calls to mobile carriers, resulting in the warning ultimately being disabled.

          @GrapheneOS , apologies fot the tagging, but this made me wonder, is this warning implemented somewhere on carrier level, or on the phone itself?
          If on the phone itself, wouldn't it be a nice addition, especially on GrapheneOS, to reimplement this 'feature' perhaps after a toggle, if seen as feasible in the first place?

          • de0u replied to this.

              Onlyfun thanks. Does the sim card work with grapheme pixels? It says it is for GL.iNet Devices though I don't see their line of phones...

              And the portable router doesn't need to be plugged into a wall, but simply can be carried in your pocket (battery operated or rechargeable) so you can use with Graphene Pixels on airplane mode WiFi secure messaging to avoid getting on someone's radar?

                  Onlyfun also can this router be set up anonymously so no identifiers are seen at protest scannings?

                      K8y thanks. Does the sim card work with grapheme pixels? It says it is for GL.iNet Devices though I don't see their line of phones..

                      Yw. I have no idea, but they say: For use with other devices or mobile phones, APN setting(wbdata) may need to be manually configured. If you need assistance, our technical support team is available at support@gl-inet.com to guide you through the process.

                      so i would give it a try, $10 doesn't seem a lot even if it fails.

                      K8y And the portable router doesn't need to be plugged into a wall, but simply can be carried in your pocket (battery operated or rechargeable) so you can use with Graphene Pixels on airplane mode

                      no wall is required afaik. as mobile as your mobile phone.

                      K8y secure messaging to avoid getting on someone's radar?

                      still detectable. anonymity is necessary to maintain. messaging as well, not only secure.

                      • K8y likes this.

                            r134a Is this warning implemented somewhere on carrier level, or on the phone itself?
                            If on the phone itself, wouldn't it be a nice addition, especially on GrapheneOS, to reimplement this 'feature' perhaps after a toggle, if seen as feasible in the first place?

                            You may be interested in this recent post about an EFF research project: https://discuss.grapheneos.org/d/20515-meet-rayhunter-a-new-open-source-tool-from-eff-to-detect-cellular-spying/

                                de0u Wow, thanks for pointing me to that thread! i've managed to miss it. This seems a very interesting project, i'll look some deeper into it and possibly install it & contribute data to it, depending on my local laws which i first have to research.

                                  I suspect the price of this device will go up significantly soon.. I wonder what's the sim compatibility since it looks to be a Verizon specific device.

                                    0xsigsev Yeah, just found out that it is a Verizon specific device, consequently i don't find availability anywhere in europe. Step 2 would have been finding out if it would be actually compatible with GSM in europe, and step 3 researching local laws, but since i can't find any availability in europe, i guess it ends here.

                                    I wonder though, as in their article they aim to collect data outside of the us aswell, but currently only support that verizon specific orbic router, how they had this in mind? Perhaps there will be more devices supported as the project grows, with actual availability outside the us?

                                        r134a I think the 'outside US' was an afterthought and they mainly focus on US.. Obviously I am not trying to shit on them on anything for that, just giving my opinion. I will most probably order one anyway and see if it is sim locked, or what's more important whether it works with the bandwidths here where I live..

                                        I also am considering reaching out to EFF asking about the possibility to use other devices.

                                            0xsigsev If u are in the position then to report back, i would highly appreciate it.

                                              @0xsigsev Hi, perhaps u are keeping an eye aswell on rayhunter and u are already aware, but i wanted to let u know anyway, since u mentioned u would probably order that orbic router, there's a good chance it will be possible to run in the near feauture to run it on a device more accesible in europe: TP-link M7350.

                                              There's a fork being created to make it run specifically for that device, and there's already a PoC it running on it: https://github.com/m0veax/rayhunter-tplink-m7350/blob/main/PoC.md

                                                r134a Thanks, I haven't had much time to look into it further so this heads up is really appreciated. Was going to order the orbit next week, so instead will wait for the fork to mature a bit.

                                                  Chipper portable 4g router

                                                  I wouldn't use one of those. The project has a thread about a lot of what's being discussed in this thread and touches on mobile routers here: https://grapheneos.social/@GrapheneOS/113319956422621755. Some relevant quotes about mobile routers are as follows:

                                                  Dedicated Hotspot devices aren't good for privacy/security.

                                                  [B]ear in mind that carrying around a Wi-Fi access point (AP) is the opposite of private. An AP has a persistent MAC even if it's random upon creating the AP such as making a hotspot with a phone. Wi-Fi does not have MAC rotation like Bluetooth Low Energy privacy extensions.

                                                  GrapheneOS uses per-connection MAC rand and per-connection DHCP as improvements over the standard Android Open Source Project. The MAC still remains the same while connected, and an AP isn't going to cycle until it's reset. Wi-Fi does not try to do what BLE privacy extensions do.