Zero Knowledge Proofs: an Illustrated Primer
Specifically, assume that I (the Verifier) have some strategy that ‘extracts’ useful information about Google’s coloring after observing an execution of the honest protocol. Then my strategy should work equally well in the case where I’m being fooled with a time machine. The protocol runs are, from my perspective, statistically identical. I physically cannot tell the difference.
Thus if the amount of information I can extract is identical in the ‘real experiment’ and the ‘time machine experiment’, yet the amount of information Google puts into the ‘time machine’ experiment is exactly zero -- then this implies that even in the real world the protocol must not leak any useful information.
