Continuous variable quantum key distribution based on optical entangled states without signal modulation

TL;DR

This paper demonstrates a novel continuous variable quantum key distribution method using entangled optical states without signal modulation, achieving secure key rates under different attack scenarios.

Contribution

First experimental demonstration of CV-QKD with entangled states without signal modulation, including theoretical analysis of security against attacks.

Findings

Achieved secret key rates of 84 kbits/s and 3 kbits/s under collective attack.

Validated security boundaries against Gaussian attacks.

Demonstrated feasibility of modulation-free CV-QKD with entangled states.

Abstract

In this paper, we present the first experimental demonstration on continuous variable quantum key distribution using determinant Einstein-Podolsky-Rosen entangled states of optical field. By means of the instantaneous measurements of the quantum fluctuations of optical modes respectively distributed at sender and receiver, the random bits of secret key are obtained without the need for signal modulation. The post-selection boundaries for the presented entanglement-based scheme against both Gaussian collective and individual attacks are theoretically concluded. The final secret key rates of 84 kbits/s and 3 kbits/s are completed under the collective attack for the transmission efficiency of 80% and 40%, respectively.