Tatami Printer: Physical ZKPs for Tatami Puzzles

TL;DR

This paper introduces Tatami printer, a physical card-based zero-knowledge proof protocol for Tatami puzzles, enabling solution verification without revealing the solutions.

Contribution

It presents a novel physical ZKP protocol for Tatami puzzles and applies it to Tatamibari and Square Jam, expanding ZKP applications to physical puzzle verification.

Findings

Developed a physical card-based ZKP protocol for Tatami puzzles

Successfully applied the protocol to Tatamibari and Square Jam puzzles

Enables solution verification without solution disclosure

Abstract

Tatami puzzles are pencil puzzles with an objective to partition a rectangular grid into rectangular regions such that no four regions share a corner point, as well as satisfying other constraints. In this paper, we develop a physical card-based protocol called Tatami printer that can help verify solutions of Tatami puzzles. We then use the Tatami printer to construct zero-knowledge proof protocols for two such puzzles: Tatamibari and Square Jam. These protocols enable a prover to show a verifier the existence of the puzzles' solutions without revealing them.