Continuous-Variable Quantum Secret Sharing Based on Thermal Terahertz Sources in Inter-Satellite Wireless Links.

Chengji Liu,Changhua Zhu,Changxing Pei,Min Nie,Zhihui Li,Hong Yang

doi:10.3390/e23091223

Abstract

We propose a continuous-variable quantum secret sharing (CVQSS) scheme based on thermal terahertz (THz) sources in inter-satellite wireless links (THz-CVQSS). In this scheme, firstly, each player locally preforms Gaussian modulation to prepare a thermal THz state, and then couples it into a circulating spatiotemporal mode using a highly asymmetric beam splitter. At the end, the dealer measures the quadrature components of the received spatiotemporal mode through performing the heterodyne detection to share secure keys with all the players of a group. This design enables that the key can be recovered only by the whole group players’ knowledge in cooperation and neither a single player nor any subset of the players in the group can recover the key correctly. We analyze both the security and the performance of THz-CVQSS in inter-satellite links. Results show that a long-distance inter-satellite THz-CVQSS scheme with multiple players is feasible. This work will provide an effective way for building an inter-satellite quantum communication network.

Highlights

Published: 17 September 2021Standard point-to-point quantum key distribution (QKD) based on the fundamental laws of quantum mechanism can achieve unconditionally secure key establishment on unsafe channels [1,2,3,4]
Similar to the original sequential continuous-variable quantum secret sharing (CVQSS), the main idea of THz-CVQSS is that each player locally preforms Gaussian modulation to prepare a standard Gaussian-modulated thermal state (GMTS) and couples it into a circulating spatiotemporal mode using a highly asymmetric beam splitter (HABS), which can be efficiently immune to Trojan horse attacks
We have presented a THz-CVQSS scheme based on thermal THz sources and heterodyne detectors, which can be efficiently immune to Trojan horse attacks

Summary

Introduction

Standard point-to-point quantum key distribution (QKD) based on the fundamental laws of quantum mechanism can achieve unconditionally secure key establishment on unsafe channels [1,2,3,4]. In 2017, Kogias et al [27] proposed the security proof of entanglementbased CVQSS against both dishonest players and eavesdroppers appeared in the channels This protocol may hard to be implemented with the current technology when the number of players is large. In this paper, inspired by Grice et al.’s work [32], we propose a CVQSS scheme based on thermal THz sources in inter-satellite wireless links (THz-CVQSS). Similar to the original sequential CVQSS, the main idea of THz-CVQSS is that each player locally preforms Gaussian modulation to prepare a standard Gaussian-modulated thermal state (GMTS) and couples it into a circulating spatiotemporal mode using a highly asymmetric beam splitter (HABS), which can be efficiently immune to Trojan horse attacks.

The Proposed Quantum Secret Sharing Protocol and Its Security

Channel Model

Secret Key Rate

Simulation and Discussion

Conclusions