Secure quantum ranging

TL;DR

This paper introduces a secure quantum ranging protocol that achieves high-precision position estimation and detects cheating, integrating quantum ranging with position verification using entangled states and simple operations for honest parties.

Contribution

It presents a novel quantum ranging protocol that combines position verification with Heisenberg-limited precision and security against sophisticated cheaters.

Findings

Achieves Heisenberg-limited position estimation precision.

Detects potential cheaters using entangled states.

Provides a framework for quantifying position verification accuracy.

Abstract

Determining and verifying an object's position is a fundamental task with broad practical relevance. We propose a secure quantum ranging protocol that combines quantum ranging with quantum position verification (QPV). Our method achieves Heisenberg-limited precision in position estimation while simultaneously detecting potential cheaters. Two verifiers each send out a state that is entangled in frequency space within a single optical mode. An honest prover only needs to perform simple beam-splitter operations, whereas cheaters are allowed to use arbitrary linear optical operations, one ancillary mode, and perfect quantum memories-though without access to entanglement. Our approach considers a previously unstudied security aspect to quantum ranging. It also provides a framework to quantify the precision with which a prover's position can be verified in QPV, which previously has been assumed to be infinite.