They can do the same with a random 64 character identifier

In theory you could get a bigger antenna (increasing your SNR) and a chip with a greater transmission power (increasing access point SNR)

In fact, Google already implemented a way to hide files: it's called "secure folder" in Files and "locked folder" in Photos.

BTW IDK why there are two names for the same concept

I was expecting something like known NPC problems and their reductions plus complexity of algorithms and data structures.

This seems like a math cheat sheet that can be improved removing simple derivations of some formulas.

However it can be handy.