Continuous-variable quantum key distribution field-test with true local oscillator

TL;DR

This paper demonstrates a practical implementation of continuous-variable quantum key distribution with a true local oscillator over a deployed fiber network, enhancing security and feasibility for real-world quantum communication.

Contribution

First experimental demonstration of true local oscillator CV-QKD over a real fiber network using off-the-shelf components.

Findings

Successful coexistence of quantum and classical signals on a single fiber

First deployment of true LO CV-QKD in a real-world fiber network

Enhanced security features by using receiver-based local oscillator

Abstract

Continuous-variable quantum key distribution (CV-QKD) using a true local (located at the receiver) oscillator (LO) has been proposed to remove any possibility of side-channel attacks associated with transmission of the LO as well as reduce the cross-pulse contamination. Here we report an implementation of true LO CV-QKD using "off-the-shelf" components and conduct QKD experiments using the fiber optical network at Oak Ridge National Laboratory. A phase reference and quantum signal are time multiplexed and then wavelength division multiplexed with the classical communications which "coexist" with each other on a single optical network fiber. This is the first demonstration of CV-QKD with a receiver-based true LO over a deployed fiber network, a crucial step for its application in real-world situations.