I’m sad to see that analogy become so popular over the last year. It fails to capture the tremendous amount of work that is required to establish or verify proofs. In the Waldo example verification is O(n).
I’ve worked on other analogies but every simplification is damning in its own way. One I particularly like:
You want to ask Google for directions to an address in your small town but you don’t want Google to know where you are going or where you live. Instead you ask for a list of directions between every address in your small town. It takes a bit longer to return these results but the it satisfies the conditions.
This isn’t of course how ZKP’s work but directionally captures their computational overhead in a way other examples don’t.
The Waldo example is more an explanation of "what" a ZKP is than "how" a ZKP works. Not a terrible starting point, but yep, definitely doesn't capture the complexity of the real deal.
The best example is to show the actual zero-knowledge protocol for something simple, e.g. graph isomorphism. The protocol is short enough that anyone looking at it can intuitively understand correctness, and from there it's not much further to verify the zero-knowledge property either.
I’ve worked on other analogies but every simplification is damning in its own way. One I particularly like:
You want to ask Google for directions to an address in your small town but you don’t want Google to know where you are going or where you live. Instead you ask for a list of directions between every address in your small town. It takes a bit longer to return these results but the it satisfies the conditions.
This isn’t of course how ZKP’s work but directionally captures their computational overhead in a way other examples don’t.