Device-independent entanglement-based Bennett 1992 protocol

TL;DR

This paper establishes a new link between Bennett 1992 protocol and Bell inequalities, extending it to an entanglement-based form with a simplified, device-independent security proof and the lowest efficiency threshold reported.

Contribution

It introduces an entanglement-based version of the Bennett 1992 protocol with a novel security proof leveraging Bell inequalities and device-independence.

Findings

Extended the Bennett 1992 protocol to an entanglement-based formulation

Provided a simple, device-independent security proof

Achieved the lowest efficiency threshold for practical implementation

Abstract

In this paper we set forth a novel connection between the Bennett 1992 protocol and a Bell inequality. This allows us to extend the usual prepare-and-measure protocol to its entanglement-based formulation. We exploit a recent result in the frame of device-independent quantum key distribution to provide a simple, model-independent, security proof for the new protocol. The minimum efficiency required for a practical implementation of the scheme is the lowest reported to date.