I’ve edited the first comment to make it more accurate.
I looked at Graphene’s FAQ page and some mitigations are practiced for cellular tracking : Frequently Asked Questions | GrapheneOS. It doesn’t prevent it, but it’s more secure and reliable than on other systems. I wasn’t aware of these features before my comment.
Airplane mode works well on recent and secure devices unless there’s a major security breach, which doesn’t seem to be the case at the moment. But I’d rather recommend a secure device than have to explain to the authorities why I have a shielded RFID, especially in a “sensitive country”..
OP’s current situation being the “authority” expressed their “interest” in OP, so at this point I would say having a “secured” device is no longer enough as the attack factors are no longer limited to phone software level.
@Gman if I were you, depending on your threat level, I might
Backup all crucial information to E2EE cloud storage, and then wipe the device and reinstall “non-sensitive” apps.
Depending on the country I’m in, I might purge my email/ messenger / social media, for any sensitive contents / contacts. If they are important, back them up to a E2EE service providers.
I would obtain a new device, use it without logging in my Google / Apple Account (if applicable), use only non-public WIFI networks with DPI resistant VPNs, then make all necessary re-arrangements on my appointments.
I would continue to bring the exposed device with me for non-sensitive journeys, and keep it connected to the network (IF it was what I have been doing), so it does not seem suspicious.
I would avoid making any non-E2EE calls and texts.
Be very mindful of public surveillance, avoid any sensitive activity/ meeting in public venues during day time.
Review my sociograph, if I have connection with actual POI of the “authority”, I might step up even further.
The only right mitigation is to ditch the phone after visit. Not per say for the IMEI alone but as a general mitigation against traveling to certain countries.
Never take your main device there. Leave it at home. Take a burner device and throw it away (read destruct it) before going home after landing.
That’s not compromised. But if authorities can ask you your IMEI, then they could ask you to unlock your phone and siphon the data. So I really recommend you do a backup of your phone data, and upload it on a secure drive like Proton Drive. Then resets your phone. This way no compromising information is on your phone, and the cops don’t know you have Proton Drive.
This is mostly true, EMF leakage can happen if it isn’t sealed properly and uses nonconductive materials like plastic or rubber. However this is probably the less suspicious if they are already targeted. Burner phone is the best option in this case.
Both IMSI and IMEI numbers can be used for tracking devices by cellular operator and by extension the state. The IMEI is better suited for this purpose since the IMSI is tied to a specific SIM card which is much cheaper to replace.
If you need a Faraday bag, you should purchase one from a reputable supplier. A random metal box is ineffective as a Faraday cage, and signals will leak out.
In the vast majority of countries it is perfectly legal to change your IMEI. You should not claim that changing your IMEI number is illegal when that simply isn’t true in most places.
Changing your IMEI is not advisable. It is at best an ineffective way to try to game the cellular network and is likely to make your device stand out more, not less.
I’m sorry but I do not see the “myth” as faraday bags and cages tend to be tuned or designed to eliminate specific frequencies from exiting the enclosure they are in.
Then you are well aware that most bands other than 5G work below 7Ghz and have a greater penetrating power than mmwave and unless that pencil box is sealed tightly with a conductive elastomer gasket, leakage is still bound to happen. The thickness of the pencil case will also play a significant role in how well it blocks out the waves.
Nope, you cannot really tuned a farady bag. In north America for example Cellular are from 600 MHz to 4 GHz range mainly. Those a vastley different wavelenght.
Tuning is not the best wording to describe this but my point is a farady bag can be designed to cover a broad range (600mhz to 5ghz) as these are the wavelength commonly used within the mobile phones. The lower you go in frequency the great the penetration power and requires extra shielding. The higher frequencies would then be more likely to be absorbed or reflect from the material than find ways to pass through it (when sealed from gaps properly*).
There are even some bags that claim to go higher and this is possible with the right design but as we get much higher into the wavelength spectrum it becomes easier for the wave to find gaps within the material. It then becomes much harder to attenuate without the correct measures but entirely possible.
These bags are becoming more and more common with actual testing behind them to ensure EMI and EMP protections from in and outside of the bag. There are scientific articles that prove this is working and international (IEEE 299-2006, IEC 61000-4-20) and military (MIL-STD-188-125-2) standards that are being used to ensure correct shielding. GoDark Faraday bags have test reports from Keystone (supposedly) an accredited certified testing facility to protect against the advertised wavelengths you claim are not able to be protected against.
I work closely with wavelengths from khz to ghz and can confirm through testing using appropriate tools such as a spectrum analyzer, an anechoic chamber, network analyzer, RF power meter and other tools needed to monitor and record this information for certified boud inspections. I have worked with the US government on ISO audits, CE governing body’s for CE marking audits and with UL regarding electromagnetic activity.
network Analyser ? lol. I have Keystone spectrum too and IEC 61000-4-20.
If anyone here look at the door of their microwave oven (2400 MHZ ISM) they will see small hole in the grid, if that would not be a good faraday cage, you will be unsafe while using it.
So why a metalic plate punched with small is ok with a 1500 watts microwave oven but a 0.5 watts phone would be able to ‘leak’ ?
This will be my last response as i will have provided enough evidence that faraday cages/bags will and do work (and we are moving off topic).
Microwaves ovens use the 2.45ghz frequency that is very specific and the “holes” are actually small enough that the emissions generally do not escape. However they have been known to leak emissions and are far from a proper faraday cage. This would lead you to the metal pencil box you described earlier. While it does stifle the signal a leak can occur within acceptable safety standards.
If you follow this standard then you will be well aware that the the faraday bag can work as intended if built properly.
So for what was stated by other people in this post regarding them, they are correct using this as a mitigation strategy for their concerns. But I do appreciate the candor you provided
