Abstract In order to enhance the physical-layer security of the communication systems in the optical fiber channel, a novel secure communication scheme based on optical code-division multiple-access (OCDMA) technology is proposed and its physical-layer security is quantitatively analyzed. Due to the small capacity of the traditional OCDMA codewords, the address code used by legitimate user is vulnerable to the brute-force searching attack. To solve this issue, a new type of 2-D wavelength-hopping/time-spreading (WH/TS) code with large capacity is constructed at first. Based on information-theoretic security, the wiretap channel model of this secure communication system is established, and the secrecy capacity is employed to evaluate the physical-layer security level. The simulation results indicate that the novel secure communication system can provide a high-speed and long-haul secure transmission and it is important to get the optimal parameter values to improve the system security.

中文翻译：

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基于光码分多址技术的新型保密通信系统设计与性能分析

摘要 为提高光纤信道通信系统的物理层安全性，提出了一种基于光码分多址(OCDMA)技术的新型安全通信方案，并对其物理层安全性进行了定量分析。由于传统OCDMA码字容量小，合法用户使用的地址码容易受到暴力搜索攻击。为了解决这个问题，首先构建了一种新型的大容量二维跳波/时间扩展（WH/TS）码。基于信息论的安全性，建立了该安全通信系统的窃听通道模型，并利用保密能力来评价物理层的安全等级。