In this letter, a novel physical layer encryption method based on digital chaos is proposed for the security in high-speed intensity modulation and direct detection (IM/DD) discrete multi-tone (DMT) transmission system. In the proposed encryption scheme, a random interleaving method is used, which further enhances the ability to encrypt the quadrature amplitude modulation (QAM) constellation and improves the transmission performance. In addition, probabilistic shaping (PS) technique is also cascaded into the encrypted transmission system for the first time. Adopting the proposed algorithm, we experimentally demonstrated the transmission of 100-Gbit/s encrypted 64QAM and PS-64QAM DMT signals over 2-km standard single-mode fiber (SSMF).

中文翻译：

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用于IM / DD数据中心内部互连的DMT中的混沌加密方案

本文针对高速强度调制和直接检测（IM / DD）离散多音（DMT）传输系统的安全性，提出了一种基于数字混沌的物理层加密新方法。在所提出的加密方案中，使用了随机交织方法，这进一步增强了对正交幅度调制（QAM）星座图进行加密的能力，并改善了传输性能。此外，概率整形（PS）技术也首次被级联到加密的传输系统中。通过采用提出的算法，我们通过实验证明了在2 km标准单模光纤（SSMF）上传输100 Gbit / s加密的64QAM和PS-64QAM DMT信号。