Not in this field but, if you're willing to sacrifice performance for security (by avoiding closed, western, hardware) how hard would it be to for a group of top hardware and software engineers to make a secure smartphone?
Id gather you could go very far with the following list:
- Proved correct micro kernel
- Encrypted messaging by default
- Encrypted memory
- Encrypted messaging between processes.
- hardware switches for modems, peripherals and battery
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