Bulletproofs – Short zero-knowledge arguments of knowledge
Zero knowledge proofs are fascinating - as a non-mathematician, I particularly enjoy real-world examples.<p>Two famous examples ("The Ali Baba Cave" and the "Two Balls and the Color Blind Friend") appear in the Wikipedia article on zero knowledge proofs [1].<p>My favorite, however, is this paper [2] on convincing another person you've found Waldo, without revealing his location and therefore ruining the game. It's extraordinarily simple: take a piece of cardboard larger than the Where's Waldo book, make a small, Waldo-sized cutout, and position the cardboard in a way that only Waldo himself is visible. As long as you don't give away the position of the book underneath the cardboard, you can prove you've found Waldo without providing _any_ information as to where he is! It's pretty great.<p>Would love to know of other real world examples. :-)<p>[1] <a href="https://en.wikipedia.org/wiki/Zero-knowledge_proof#The_Ali_Baba_cave" rel="nofollow">https://en.wikipedia.org/wiki/Zero-knowledge_proof#The_Ali_B...</a>
[2] <a href="http://www.wisdom.weizmann.ac.il/%7Enaor/PAPERS/waldo.pdf" rel="nofollow">http://www.wisdom.weizmann.ac.il/%7Enaor/PAPERS/waldo.pdf</a>