akc3n IMEI is not the only hardware identifier for the device available to the cellular network. Changing the IMEi alone isn't enough to hide the device identity from the network. It will only hide one commonly used ID rather than making the device not uniquely identifiable. (ref)
Carriers often detect device model via IMEI and multiple other ways as part of their standard operating procedure. They change how things work based on the detected capabilities but also hard-wired quirks for device models, etc. Devices send a lot of info on capabilities. (ref)
It just means that future cellular modders will have to maintain trustworthy IMEI profiles/generators with common prefixes, like you see in User-Agent spoofers, etc. If IMEI is not the only identifier, we have to first figure out the full list, and whether they're spoofable on common hardware/make a 3rd-party cell-router behave like a phone (a.k.a transmit one of the common profiles).
akc3n hmop - IMEI randomization is a poor way to improve privacy and will draw attention to yourself in practice. If you want a fresh identity for the cellular network, there isn't really much alternative to using both a fresh device and SIM.
It's correct because it's cheaper until some breakthrough from the community. The amount of research someone has to do to correctly spoof all of the identifiers right (I'm not a big expert, but it seems so) on a 4G router/crackable phone is heavier than constantly replacing burner hotspot phones together with their disposable SIMs.
It's probably the way to go now - have one hardened phone and only use Wi-Fi with all of the MAC, DNS, IP protections. For connection, just use cheap phones/SIM pairs that can be changed based on the requirements + all of the precautions I won't mention.
akc3n That's a hacked together method that requires root
Just hacked together like a classic modding tool. It's amazing to see any research whatsoever in this direction, isn't it? And it's also amazing that it's mounted on a partition that can be modified from software... Not a hardware guru, but isn't it not obvious for this kind of modification?
Sounds like once eSIMs are the only option (not so soon), this topic will get more attention from the community (if hardware allows that too). From reading related topics there are many ways to achieve that on multiple devices (phones or routers), but it honestly looks cheaper to just avoid cellular networks as much as possible. They're just awful for privacy. Unless you have a lot of time to dig into protocols and vendors.
Maybe one day it's enough demand for modders to start generalize this topic and maintain a list of modifiable devices, common profile generators and a lot of guides, like Android rooting back then. Looks like not many care enough yet. A 3rd-party programmable router with a database of common profiles and eSIM support is one of the possible ways to go.