Lei Yu-Ting, Li Xiang-Jie, Pan Xing-Bo, Zhang Yun-Rong, Long Gui-Lu
State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China.
Future Research Lab, China Mobile Research Institute, Beijing 100053, China.
Entropy (Basel). 2025 Mar 22;27(4):332. doi: 10.3390/e27040332.
As a novel paradigm in quantum communication, quantum secure direct communication (QSDC) enables secure, reliable, and deterministic information transmission, leveraging the principles of quantum mechanics. One-photon-interference QSDC is particularly attractive because it mitigates the vulnerabilities in measurement devices while extending transmission distances. In this paper, we propose a high-dimensional one-photon-interference QSDC protocol that exploits the advantages of high-dimensional encoding in the phase of weak coherent pluses to further enhance transmission distances and improve secrecy channel capacity. The security of this protocol is analyzed using quantum wiretap channel theory, and its resistance to common quantum threats is discussed. Numerical simulations demonstrate that our protocol outperforms its predecessor in terms of its secrecy capacity and extends the maximum communication distance achievable up to 494 km, which is over 13% longer than the two-dimensional case, effectively doubling the transmission length of traditional protocols. These improvements highlight the protocol's potential for use in quantum communication applications in this era of frequent data breaches and information leaks.
作为量子通信中的一种新型范式，量子安全直接通信（QSDC）利用量子力学原理实现安全、可靠且确定的信息传输。单光子干涉量子安全直接通信尤其具有吸引力，因为它在扩展传输距离的同时减轻了测量设备中的漏洞。在本文中，我们提出了一种高维单光子干涉量子安全直接通信协议，该协议利用弱相干脉冲相位中的高维编码优势，进一步增加传输距离并提高保密信道容量。使用量子窃听信道理论分析了该协议的安全性，并讨论了其对常见量子威胁的抗性。数值模拟表明，我们的协议在保密容量方面优于其前身，并且将可实现的最大通信距离延长至494公里，比二维情况长超过13%，有效地使传统协议的传输长度翻倍。这些改进凸显了该协议在这个数据频繁泄露和信息泄漏时代的量子通信应用中的潜力。
