Interactive Physical Zero-Knowledge Proof for Norinori

Abstract

Norinori is a logic game similar to Sudoku. In Norinori, a grid of cells has to be filled with either black or white cells so that the given areas contain exactly two black cells, and every black cell shares an edge with exactly one other black cell. We propose a secure interactive physical algorithm, relying only on cards, to realize a zero-knowledge proof of knowledge for Norinori. It allows a player to show that he or she knows a solution without revealing it. For this, we show in particular that it is possible to physically prove that a particular element is present in a list, without revealing any other value in the list, and without revealing the actual position of that element in the list.