Relativistic Position Verification with Coherent States

TL;DR

This paper presents a quantum and relativistic protocol for secure position verification, demonstrating its practical feasibility with experimental results that surpass classical limitations, enabling secure applications in various fields.

Contribution

It introduces a novel quantum-relativistic position verification protocol using coherent states and experimentally validates its security and accuracy over 2 km.

Findings

Secure position verification achieved with 75-meter accuracy

Protocol utilizes phase-randomized weak coherent states

Experimental realization confirms practical feasibility

Abstract

Determining the position of an entity is a fundamental prerequisite for nearly all activities. Classical means, however, have been proven incapable of providing secure position verification, meaning that a prover can mislead verifiers about its actual position. In this work, we propose and experimentally realize a secure position-verification protocol that leverages quantum optics and relativity within an information-theoretic framework. Using phase-randomized weak coherent states, two verifiers separated by 2 km securely verify the prover's position with an accuracy better than 75 meters. These results establish secure position-based authentication as a practical possibility, paving the way for applications in financial transactions, disaster response, and authenticated secure communications.