Quantum Key Distribution using Expectation Values of Super-classical GHZ States

TL;DR

This paper introduces a quantum key distribution protocol leveraging expectation values of GHZ states with continuous variables, enhancing security through absolute violation detection of eavesdroppers.

Contribution

It presents a novel QKD scheme based on maximally entangled GHZ states with continuous degrees of freedom, improving eavesdropper detection methods.

Findings

Protocol enables secure key sharing among multiple parties.

Uses absolute violation for eavesdropper detection.

Increases security over probabilistic violation methods.

Abstract

We propose a new quantum key distribution scheme that is based on the optimum expectation values of maximally entangled Greenberger-Horne-Zeilinger states. Our protocol makes use of the degrees of freedom in continuously variable angles, thereby increasing the security of the key distribution. Outlined are two protocols that distribute a key from Alice to Bob using the above idea, followed by an extension that allows for the same key to be shared with Charlie. We show how this scheme provides for certain detection of any eavesdropper through absolute violation rather than the probabilistic violation used in many protocols.