A quantum key distribution scheme based on tripartite entanglement and violation of CHSH inequality

TL;DR

This paper proposes a two-way quantum key distribution protocol using tripartite GHZ states, enhancing key sharing efficiency and enabling eavesdropping detection via CHSH inequality violation in a device-independent framework.

Contribution

It introduces a novel QKD scheme based on tripartite entanglement that extends the E91 protocol with increased shared bits and device-independent security features.

Findings

Enhanced secret key rate compared to standard protocols

Effective eavesdropping detection through CHSH violation

Extension of E91 protocol with tripartite GHZ states

Abstract

Entanglement is a well-known resource in quantum information, in particular it can be exploited for quantum key distribution (QKD). In this paper we define a two-way QKD scheme employing GHZ-type states of three qubits obtaining an extension of the standard E91 protocol with a significant increasing of the number of shared bits. Eavesdropping attacks can be detected measuring violation of the CHSH inequality and the secret key rate can be estimated in a device-independent scenario.