What is the maximum amount of imformatiom about a user and the user's phone that can be obtained by a wireless carrier on a GSM network? Here is a list of the things I know, but are there more?
- IMEI, a theoretically unique identifier of the phone. Can, however, be spoofed om many phones.
- IMSI, an identifier embedded into the SIM card. Can be changed by swapping SIM cards, and if done at the same time as IMEI is spoofed to another one, should make tracing the chamge difficult.
- Data about calls and SMS as the carrier must process it in order for calling/SMS to work. Not much can be done about it.
- Device location, by triangulating it's position based on signal strength. Nothing can be done to prevent the carrier from accessing it, either.
What can be done to minimize the amount of sensitive data available to the carrier? Again, is there anything more than what I already know?
- If possible, use an encrypted chat app such as Signal instead of regular calls or SMS
- Regularly discard and change the SIM card, taking care to change the IMEI at the same time.
Anything more that can be done, while still having a working phone number? What data is still leaked?