发表机构
Henan Key Laboratory of Quantum Information and Cryptography, IEU; State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Key Lab of Navigation and Location Services, Department of Electronic Engineering, Shanghai Jiao Tong University（IEU量子信息与密码学河南省重点实验室; 上海交通大学电子工程系先进光通信系统与网络国家重点实验室上海导航与定位服务重点实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究针对QKD系统的编码、强度调制等缺陷，提出基于算子主导法的统一框架，实现密钥率紧致估计，验证了其在MDI-QKD中的鲁棒性，推动QKD实际应用部署。
AI 中文摘要
量子密钥分发（QKD）基于量子力学原理，为量子信道上的安全通信提供了一种途径。然而，QKD系统中不可避免的缺陷会引入关键漏洞，对QKD在实际安全与性能方面的部署构成重大挑战。本研究针对调制空间存在缺陷的实际场景，对QKD开展全面的安全性分析，具体聚焦于与编码、强度调制及其表征相关的缺陷。我们提出一种基于算子主导法的统一框架，以克服这些问题并实现对密钥率（SKR）的紧致估计。仿真结果表明，采用商用QKD系统表征的参数时，实际场景下的SKR与理想条件下的SKR高度吻合；在有限码长情况下，当总脉冲数N=10^12时，最大传输距离可达250 km，而当N=10^14时，SKR在250 km范围内接近渐近极限，验证了我们的方法对态制备与表征缺陷的鲁棒性。此外，还证明了该方法在测量设备无关（MDI）QKD中的可行性与鲁棒性。本分析不仅推动了实际安全与性能提升的进展，还凸显了QKD实际应用部署的可行性。
英文摘要
Quantum key distribution (QKD) offers an approach for secure communication over quantum channels, based on the principles of quantum mechanics. However, the inevitable imperfections in QKD systems can introduce critical vulnerabilities, posing significant challenges to the deployment of QKD in terms of both practical security and performance. In this work, we present a comprehensive security analysis of QKD in the practical scenarios involving imperfections in modulation spaces. Specifically, our analysis focuses on the imperfections related to encoding, intensity modulation, and their characterization. We provide a unified framework based on the operator dominance method to overcome these issues and achieve a tight estimation of the secret key rate (SKR). The simulation results show that the SKR in practical scenarios, with parameters characterized from commercial QKD systems, closely matches the SKR under ideal conditions. In the finite case, the maximum transmission distance can reach up to 250 km with total pulse number $N=10^{12}$ and the SKR closely approaches the asymptotic limit up to 250 km with $N=10^{14}$. This validates the robustness of our method against imperfections in state preparation and characterization. Furthermore, the feasibility and robustness of method in measurement-device-independent (MDI) QKD have also been demonstrated. Our analysis not only promotes advancements in enhancing practical security and performance but also highlights the feasibility of deploying QKD for actual applications.
Journal refPhysical Review A, 2026
