MCSP

Now switched to "Britain + Ireland," thanks!

Will look into this. Did it happen on the first page (map of Britain + Ireland)?

Hmm, my guess is you're trying to use the box's borders as lines (they don't count, only the lines you draw count). Let me know if that's not the issue. Also, I'll think about ways to make this more clear!

Switched to "Britain + Ireland"!

Good catch -- I'll look into this!

Very glad you enjoyed it!

For the ZK example, the math behind it is this: if there are m bordering regions and I am lying, you have a 1/m chance of catching me each time. Thus after k repetitions the chance you haven't caught me is (1-1/m)^k \approx e^{-k/m} which is extremely small for k sufficiently larger than m.

Now, you may rightfully say: hey that's still not a "proof," you could still be lying! There are two responses to this:

1. The probability can be made incredibly small, like smaller than the the chance, say, your computer got hit by a gamma ray burst that would flip bits from 0 to 1 (I really have no idea if this actually happens but people have said it to me).

2. It turns out it is mathematically impossible to get the zero knowledge property if you want true proofs (i.e., no probability of being wrong). So, there's a trade off: if you want zero knowledge, you have to accept some (small) failure probability

P.S. Adding an easter egg for coloring the larger graph is on the todo list :)

You're exactly right. The definition via primes ensures there is only one color consistent with each number (formally, this is called a perfectly binding commitment scheme). Also, here's the link if you want to go back: rahulilango.com/coloring/zk

Thanks for the feedback! As hcs suggests, this is part of the physical post-it assumption. I'll think about ways to make it more clear -- adding an FAQ is a good idea :)

Good point! I'll try to think about a better way to phrase this (happy to hear suggestions)

Thanks for pointing this out! Switched to "British Isles" -- update should be percolating now

Whoops! Switched to "British Isles" -- update should be percolating now