Preventing impossible game levels using cryptography

I had to skim down 3500 words to figure out that this article was just trying to explain PKI and isn't actually interesting to me as I already know how asymmetric encryption and signatures work.

The title is meant to be fun, I get that, but a subtitle a la "Explaining public-key infrastructure with a game example" would have clued me in and saved everyone some time...

The story is also a bit, idk. First spend three screenfuls of text walls and diagrams explaining what public key encryption is and then have another participant say "but we knew that already". It might have something to do with the cynical voice in my head going "you don't say", but it also makes me wonder why they didn't cut the explaining person off after the first two sentences. The story doesn't really seem to work.