Quantum Key Distribution based on Single Photon Bi-partite Correlation

TL;DR

This paper introduces a quantum key distribution protocol using bi-partite correlation of single photons, leveraging intensity correlation and photon counting to enhance security and communication distance.

Contribution

The paper proposes a novel prepare-measure-guess-verify (PMGV) protocol utilizing bi-partite photon correlation for secure quantum key distribution.

Findings

Protocol achieves secure key sharing with photon counting.

Fiber-based correlated photon pairs improve security and distance.

Use of attenuated laser light demonstrates practical implementation.

Abstract

We present a scheme for key distribution based on bi-partite correlation of single photons. Alice keeps an ancilla photon and sends a signal photon to Bob, where intrinsic bi-partite correlation of these photons is obtained through first order intensity correlation in their detectors. The key bits are distributed through sharing four bi-partite correlation functions and photon counting. The scheme consists of two parts; first, Alice prepares deterministic photon states and Bob measures the photon states based on his random choice on correlation functions. Second, Alice guesses Bob's choice of correlation functions and sets the key bits by sending out photon states. Bob verifies the key bits through the photon states regardless Alice made a right or wrong guess. We called this key distribution scheme as prepare-measure-guess-verify (PMGV) protocol. We discuss the protocol by using a highly attenuated laser light, and then point out the advantages of using a fiber based correlated photon-pair to achieve better performance in security, communication distance and success rate of key distribution.