基于NOMA的级联式混沌增强加密通信技术

混沌加密能够灵活地兼容多种调制格式、实现多维度数据加密，已成为军事保密光通信中有效保护数据传输的物理层加密技术。为保证光通信系统中数据传输的安全性，提出一种基于非正交多址（non-orthogonal multiple access，NOMA）的级联式混沌增强加密通信技术。通过提升混沌序列的非线性动力学特性缓解混沌本振退化问题，采用功分复用技术实现对密钥的分发和对加密数据的传输，利用三维级联混沌系统对比特、星座、子载波进行加密掩蔽。实验结果表明，该技术能够在2 km的七芯光纤上实现65.8 Gb/s的加密信号传输，密钥空间达到10^78，系统的安全性能明显提高。该项技术在军事保密光通信中具有良好的应用前景。

Cascaded Chaotic Enhanced Encryption Communications Technology Based on NOMA

Chaotic encryption has become an effective physical layer encryption technology for protecting data transmission in military secure optical communications due to its flexibility in compatibility with multiple modulation formats and data encryption on multiple dimensions. To ensure the safety of data transmission in optical communications system, this paper proposes a cascaded chaotic enhanced encryption technology based on non-orthogonal multiple access (NOMA) technology. By improving the nonlinear dynamic characteristics of chaotic sequences, the problem of chaotic local oscillator degradation is alleviated. The power division multiplexing technology is used to distribute keys and transmit encrypted data. A three-dimensional cascaded chaotic system is used to encrypt and mask bits, constellations, and subcarriers. The experimental results show that the proposed scheme can achieve 65.8 Gb/s encrypted signal transmission on a 2 km 7-core fiber with a key space of 10^78, and the security performance of the system has been significantly improved. This scheme will have good application prospects in future military secure optical communications.