there is no such thing as a zero-trust society (although I now want to write that scifi story and tease that idea out).
It’s been done, kinda. Guy named Hannu Rajaniemi wrote a dilogy called “Jean le Flambeur.” I think it’s in the second book, The Fractal Prince, the lead character visits Mars, which has a society where everyone has the ability to encrypt and/or sign all interactions; citizens have an organ that facilitates this, making the operations as fluid and natural as speaking. It’s well thought out, well written, and the series is an entertaining read. It reminded me of John C Wright’s “The Golden Oecumene” trilogy.