Baseband Processors have very weak overall security(closed-source firmware, no audits etc.)
It also gives the telecom operator very high privileges on a mobile device.
So, now I use 2 phones. First one being a 'relay' which has a SIM card, and connects to the internet normally. I turn this phone into a Wi-Fi hotspot and then connect the second phone to the Wi-Fi network of the first phone.
And this second phone is actually the personal device which I will use for open-source E2E encrypted communications, web-surfing and other normal mobile phone usage.
This second phone is not going to have a SIM card, have a custom ROM, and all other radio-communications(except for Wi-Fi) switched off always.
Will this method strip the telecom provider of the first phone(which was my main SIM card) off of any 'super-powers' they have on my phone(the second phone) through the baseband processor?
- I know the risk of an unlocked bootloader, so please do not mention that.
- I cannot trust my telecom provider at all.
- I change the first phone's hotspot's SSID and Password every 24 hours.