Experimental relativistic zero-knowledge proofs with unconditional security

Zero-knowledge proofs (ZKPs) are widely applied in digital economies, such as cryptocurrencies and smart contracts, for establishing trust and ensuring privacy between untrusted parties. However, almost all ZKPs rely on unproven computational assumptions or are vulnerable to quantum adversaries. We propose and experimentally implement an unconditionally secure ZKP for the graph three-coloring problem by combining subset relativistic bit commitments with quantum nonlocality game. Our protocol achieves a linear relationship between interactive rounds and the number of edges, reducing round complexity and storage requirements by thirteen orders of magnitude, thereby significantly enhancing practical feasibility. Our work illustrates the powerful potential of integrating special relativity with quantum theory in trustless cryptography, paving the way for robust applications against quantum attacks in distrustful internet environments.