Du Ji, Wang Yuan, Fei Chao, Chen Ruilin, Zhang Guowu, Hong Xiaojian, He Sailing
Opt Express. 2021 Jan 18;29(2):783-796. doi: 10.1364/OE.416117.
In this paper, a low-complexity two-level chaotic encryption scheme is introduced and experimentally demonstrated to improve the physical layer security of a 450-nm laser underwater optical wireless communication (UOWC) system using discrete Fourier transform spread discrete multi-tone (DFT-S DMT) modulation. In the first encryption stage, the original bit stream is encrypted with a chaotic sequence based on a one-dimensional Logistic map. In the second encryption stage, the real and imaginary components of the DFT-S symbols are further encrypted with a pair of separate chaotic sequences, which are generated from a two-dimensional Logistic iterative chaotic map with infinite collapse (2D-LICM). The experimental results indicate that the encryption operation has no negative effect on the performance of the proposed UOWC system. For chaotic encryption, the DFT-S DMT gives a better performance than the DMT scheme under different water turbidities. 55-m/4.5-Gbps and 50-m/5-Gbps underwater transmissions are successfully demonstrated by the chaotic encrypted DFT-S DMT scheme. To the best of our knowledge, this is the first time to verify the feasibility of chaotic encryption in a high-speed UOWC system.
本文介绍并通过实验演示了一种低复杂度的两级混沌加密方案，以提高采用离散傅里叶变换扩频离散多音（DFT-S DMT）调制的450纳米激光水下光无线通信（UOWC）系统的物理层安全性。在第一级加密阶段，原始比特流使用基于一维逻辑斯谛映射的混沌序列进行加密。在第二级加密阶段，DFT-S符号的实部和虚部分别使用一对独立的混沌序列进一步加密，这对混沌序列由具有无限坍缩的二维逻辑斯谛迭代混沌映射（2D-LICM）生成。实验结果表明，加密操作对所提出的UOWC系统的性能没有负面影响。对于混沌加密，在不同水浑浊度下，DFT-S DMT比DMT方案具有更好的性能。混沌加密的DFT-S DMT方案成功实现了55米/4.5吉比特每秒和50米/5吉比特每秒的水下传输。据我们所知，这是首次在高速UOWC系统中验证混沌加密的可行性。
