Liu Chengji, Zhu Changhua, Nie Min, Yang Hong, Pei Changxing
Opt Express. 2022 Apr 25;30(9):14798-14816. doi: 10.1364/OE.454564.
Continuous-variable quantum key distribution (CVQKD) can be effectively compatible with off-the-shelf communication systems and has been proven to be the security against collective attacks in the finite-size regime and composability. In this paper, we classify three different trust levels for the loss and noise experienced by the sender and receiver. Based on these trust levels, we derive the composable finite-size security bounds of inter-satellite CVQKD in the terahertz (THz) band. We also show how these trust levels can nontrivially increase the composable secret key rates of THz-CVQKD and tolerate higher loss. Furthermore, the numerical simulations strongly support the feasibility of inter-satellite THz-CVQKD even in the worst trust level. This work provides an efficient path for building an inter-satellite quantum communication network.
连续变量量子密钥分发（CVQKD）能够有效地与现成的通信系统兼容，并且已被证明在有限尺寸条件下针对集体攻击具有安全性和可组合性。在本文中，我们对发送方和接收方所经历的损耗和噪声的三种不同信任级别进行了分类。基于这些信任级别，我们推导了太赫兹（THz）频段卫星间CVQKD的可组合有限尺寸安全界限。我们还展示了这些信任级别如何能显著提高太赫兹CVQKD的可组合密钥率并容忍更高的损耗。此外，数值模拟有力地支持了即使在最差信任级别下卫星间太赫兹CVQKD的可行性。这项工作为构建卫星间量子通信网络提供了一条有效途径。
