Experimental Implementation of A Quantum Zero-Knowledge Proof for User Authentication

TL;DR

This paper presents an experimental quantum zero-knowledge protocol for user authentication, demonstrating its implementation on current quantum devices, analyzing security, and validating performance over various distances.

Contribution

It introduces a practical quantum zero-knowledge authentication protocol, experimentally implemented and tested on existing quantum cryptographic hardware.

Findings

Quantum bit error rate increases by ~25% with malicious players

Protocol effective over distances up to 60 km

Security properties like completeness and soundness validated

Abstract

A new interactive quantum zero-knowledge protocol for identity authentication implementable in currently available quantum cryptographic devices is proposed and demonstrated. The protocol design involves a verifier and a prover knowing a pre-shared secret, and the acceptance or rejection of the proof is determined by the quantum bit error rate. It has been implemented in modified Quantum Key Distribution devices executing two fundamental cases. In the first case, all players are honest, while in the second case, one of the users is a malicious player. We demonstrate an increase of the quantum bit error rate around 25% in the latter case compared to the case of honesty. The protocol has also been validated for distances from a back-to-back setup to more than 60 km between verifier and prover. The security and robustness of the protocol has been analysed, demonstrating its completeness, soundness and zero-knowledge properties.