This doesn't seem like a problem with a technical solution. If he slips up and gets caught, that alone might be enough to send him into a Xinjiang concentration camp.

Some of my libertarian tech friends like the idea of more encryption and decentralisation to resist what they perceive as increasingly oppressive governments, but I'm confident that this tech-first approach can never work. A truly oppressive government can easily outlaw these things and identify the users, and they'll be the first to disappear.