Funny that none of the cloud service providers has put that forward as a way to restore their credibility.
How would you do it? Please share(if it's OK).
Considering the grave threat to US online services' from lack of trust, you would think that some announcement in this direction might have been made. Crickets, so far.
I'd be more worried about peripherals.
Telephones are hard to secure. That's why I mentioned open firmware. I'm not an expert on hardware-level security, but the combination of SoC architecture and lots of programmable cores in peripherals makes me think you would find ways of extracting information from a device that way. And the mobile baseband controls some of the audio paths in a handset.
It will be interesting to see if there are any revelations about device-makers and security that come out of the heightened interest in this topic.