Secure Enclave is not a new concept.

> The only realistic way to guarantee this sort of thing is to reverse engineer the entire chain between the two and then never install any software updates.

Reverse engineer the hardware and not change it, that's the whole point, it's not in the software, only queries after the keyword are passed forward (if I'm understanding correctly, gee I don't even like apple much, things I choose to spend my time on..)