近日，丹麦技术大学Gehring, Tobias团队研究了基于离散调制连续变量量子密码的实验可组合密钥分配。2025年7月28日，《光：科学与应用》杂志发表了这一成果。

建立安全的数据通信需要在公共通道上进行安全的密钥交换。利用量子物理原理的量子密钥分发（QKD）可以在具有信息论安全性的情况下实现这一目标。特别是离散调制（DM）连续变量（CV） QKD协议，由于其简单性和与标准高速电信技术的兼容性，是大规模部署量子安全通信的合适候选。

研究组首次实验演示了四态差分测量（DM）连续变量量子密钥分发（CVQKD）系统，该系统成功生成了可组合的有限大小密钥，在20公里光纤信道和2.3×10⁹个相干量子态的条件下，能够抵御集体攻击，实现了11.04×10^-3比特/符号的正可组合密钥率。这一成就得益于先进的安全证明，精心选择其参数，以及系统的快速稳定运行。该研究结果标志着大规模部署实用、高性能、经济高效和高度安全的量子密钥分配网络的重要一步，这些网络以标准电信组件为主题。

附：英文原文

Title: Experimental composable key distribution using discrete-modulated continuous variable quantum cryptography

Author: Hajomer, Adnan A. E., Kanitschar, Florian, Jain, Nitin, Hentschel, Michael, Zhang, Runjia, Ltkenhaus, Norbert, Andersen, Ulrik L., Pacher, Christoph, Gehring, Tobias

Issue&Volume: 2025-07-28

Abstract: Establishing secure data communication necessitates secure key exchange over a public channel. Quantum key distribution (QKD), which leverages the principles of quantum physics, can achieve this with information-theoretic security. The discrete modulated (DM) continuous variable (CV) QKD protocol, in particular, is a suitable candidate for large-scale deployment of quantum-safe communication due to its simplicity and compatibility with standard high-speed telecommunication technology. Here, we present the first experimental demonstration of a four-state DM CVQKD system, successfully generating composable finite-size keys, secure against collective attacks over a 20km fiber channel with 2.3×109 coherent quantum states, achieving a positive composable key rate of 11.04×103 bits/symbol. This accomplishment is enabled by using an advanced security proof, meticulously selecting its parameters, and the fast, stable operation of the system. Our results mark a significant step toward the large-scale deployment of practical, high-performance, cost-effective, and highly secure quantum key distribution networks using standard telecommunication components.

DOI: 10.1038/s41377-025-01924-9

Source: https://www.nature.com/articles/s41377-025-01924-9