"You know what the chain of trust is?
It's the chain I go get and beat you with 'til ya understand who's trustin' who here."

(lightly laundered Jane Cobb Firefly quote in article about bungled cryptography.)

3 quick takeaways FTA.

-- 1 Applied cryptography cannot solve a security problem. It can only convert a security problem into a key-management problem.
-- 2 Chains of trust are directional. Do not invert them.
-- 3 Unexplainable security features are just marketing materials.

Point 1 is the most illuminating imho.