[throwaway41597]

The PinePhone looks compelling indeed.

One question: does anyone know where encryption occurs for 4G and Bluetooth voice for example? Is audio going to a BT headset encrypted inside the BT chip? Is audio going to the 4G network encrypted inside the modem?

Edit: Thanks for your replies.

[RL_Quine]

There's not really any meaningful encryption in LTE in the real world, that there is is vulnerable to all sorts of nasty downgrade attacks. You're better forgetting there is any and assuming that it's all in cleartext. Any there is will be deciphered on the radio hardware and then send in the clear to the main processor. This is how it always works.

The point of the pinephone post here is that you're basically treating the entire modem as untrusted and part of the internet rather than part of your device, which is the correct approach.

[squarefoot]

This is possible, although if the user has control over the "trusted" part of the system, nothing prevents the data to be encrypted before leaving it. That is, suppose we know the radio chip contains the encryption code, but also some suspicious closed firmware we cannot examine; since we can't trust that chipset, we could add one more encryption layer on the data before it reaches the untrusted chipset, so that any potentially malicious firmware would see essentially random noise. Of course the other end must employ the same decryption scheme, which is not immediate for sure, but still doable and would make extremely difficult for anyone to snoop our data.

The point is: we can't have a 100% fully open and auditable system, both in HW and SW, so they built a fence to separate the trusted hardware in which we work with our data and the untrusted but necessary part where our data can't enter before being encrypted.

It's a huge effort, which brings us one more time on the importance of having full open hardware/firmware/software. I wonder if current technology would allow crowfunding the creation of fully open chipsets. Nothing immediate, just one damn chip at a time: networking today, storage controllers in two years, graphics in 5, etc.

[kop316]

I would assume each would happen inside the BT chip and inside the modem, respectively.