高速混沌保密通信收发系统密钥空间增强研究

The demand drives the continuous development of secure communication technology. For symmetric cryptography, there exists the difficulty of key secure distribution. Asymmetric cryptography faces a challenge of the slow encryption. Quantum secure communication is confronted with the technological bottlenecks of low key generation rate. Compared with the above-mentioned encryption technologies, chaotic secure communication has some striking advantages, such as high transmission rate, long transmission distance and compatibility with the existing fiber networks. However in the present chaotic secure communication system, structural parameters of transmitter/receiver system are utilized as the secret key, which gives rise to the low security key space. To increase the security key space, some methods like modulating the feedback phase by the pseudorandom series or adding the complicated optical component in the feedback loop are actively explored. But they all have various limitations, for example, the limited increase of the security key space, the poor integrated level, or no guarantee of system consistency..This project proposes a new method of the security key space enlargement by using an integrated multi-section cascade coupled semiconductor laser (MSCCSL) as the transmitter/receiver system of chaotic secure communication. Moreover, operating parameters of the transmitter/receiver system are served as the security key instead of their structural parameters. The security key space is increased to above 2^50 by independently tuning the multiple operating parameters of the MSCCSL to control the output state of the MSCCSL. Besides, the dynamic characteristics of the MSCCSL and the condition of the chaos synchronization between two MSCCSLs are investigated, and thus the optimal design and the integrated scheme of the MSCCSL are given. The crack probability of chaotic system is further analyzed and the efficient codification scheme of the high-speed message is explored. Finally, the experimental verification of chaotic secure communication for 10-Gbps transmission rate and 100-km transmission distance is achieved. .This project will provide theoretical support and technological implementation scheme for the practicability of chaotic secure communication.

需求推动着保密通信技术的不断发展。对称加密存在密钥安全分发难题，非对称加密速度较慢，量子密钥分发面临密钥生成率低等技术瓶颈。混沌光纤通信具有硬件加密、与现行高速长距离光通信技术兼容等优点，但以光收发器的结构参数为密钥导致密钥空间过小。通过伪随机码调制或在反馈环嵌入复杂元件等方法是扩大密钥空间的有益尝试，又引发集成程度差、一致性无法保证等问题。.我们提出工作参数协同结构参数，扩大收发器密钥空间的思想。设计新型的多区级联耦合腔半导体激光器(MSCCSL)，通过MSCCSL的多参数组合调控，构建密钥空间超过2^50的混沌通信收发模块。分析MSCCSL的动力学特性，研究高相关混沌同步的实现条件，优化MSCCSL设计和光子集成实现方案；探索高速信息加载与解调方式，评估系统的安全性，完成10Gb/s、100km混沌保密通信实验验证。.项目研究将为发展高速混沌光纤保密通信提供理论支撑和技术解决方案。

保密通信一直是人类孜孜追求的目标。量子密钥分发因有望解决密钥安全分发而备受关注，但存在密钥分发速率过低等应用瓶颈。混沌光保密通信是基于通信双方建立的混沌同步，通过用类噪声的混沌激光信号来掩藏信息的一种保密通信技术。它因具有硬件加密、传输速率高、长距离以及与现有光纤网络兼容等优点而受到广泛关注。但现存方案多采用镜面反馈激光器作为混沌收发机，其密钥空间不足严重制约了高速混沌光保密通信的实用化进程。. 为此本项目开展了以下工作：提出分别利用多区级联互耦合激光器(MSCCSL)、啁啾光纤光栅(CFBG)反馈混沌半导体激光器、可编程的光电反馈混沌半导体激光器作为混沌通信的收发机，实现密钥空间增强的混沌保密通信，其密钥空间分别可达2^70、2^50和2^100。通过构建MSCCSL理论模型，研究了MSCCSL的动力学特性，获得了宽带混沌产生的途径。结合理论分析，项目成功研制了光子集成的互耦合混沌激光器，实现了宽带混沌激光的产生。此外，利用CFBG反馈半导体激光器实验上获得了带宽＞20 GHz，平坦度＜3 dB的宽带混沌信号。通过CFBG反馈混沌激光器共驱同步实现了传输距离为100km，速率为40Gb/s信息混沌通信的实验验证。. 项目执行期间，获山西省技术发明一等奖1项，二等奖1项；发表期刊论文47篇；授权美国专利3件，国家发明专利13件；项目组成员晋升教授1人、副教授3人；培养博士研究生5人，硕士研究生12人。. 本项目的研究将为发展高速混沌光纤保密通信提供理论支撑和技术解决方案。