Research On High-Speed Secure Communication Based On Chaotic Spectral Phase Encryption

With the rapid development of various emerging technologies,information security has become an important national strategic issue.Secure communication is an important technology for the realization of information security.Chaotic communication has been one of the hot research topics in the field of secure communication,since it can improve the physical layer security of communication systems.Semiconductor lasers subject to external perturbation can generate stable chaotic signals,and have been widely applied in chaotic communications.However,with the development of continuous researching,the traditional chaotic communication system has begun to show some limitations in the impelment of high-speed long-distance transmission.On one hand,the bandwidth of chaos is limited by the intrinsic laser relaxation oscillation,which limits the capacity of chaotic communication.On the other hand,the broadband chaotic signal is sensitive to fiber dispersion,which degrades the compatibility between traditional chaotic communication and the fiber transmission system,and then limits the communication distance.Therefore,it is of great importance to explor new high-speed chaotic communication systems.In this thesis,on the basis of spectral phase encoding technology,we firstly studied the the physical mechanism of chaotic spectral phase encryption(CSPE),by taking the encryption of OOK signals for instance.After that,four different CSPE configurations are discussed,in virtue of the sensitivity characteristics of QPSK signals and 16 QAM signals.Combined with the common chaotic laser-driven synchronization mechanism and spectral phase encryption technology,the simulation platform for point-to-point optical CSPE communication system is constructed,and the encryption performan for the four CSPE configures are discussed and we choose dispersion+phase modulation(PM)configuration with the excellent communication performance and security as the CSPE investigated thoroughly in the following sections.Next,the chaotic synchronization performance,communication performance and security performance in the CSPE secure communication system are studied,and the maximum transmission rate and the longest distance of the CSPE secure communication system are studied.On the basis of the simulation results,we establish an experimental sytem to confirm the further feasibility of the CSPE secure communication system.By taking the QPSK modulation format as an example,secure transsion for25Gbit/s QPSK signal over50 km single-mode optical fiber is experimentaly demonstrated.In addition,the wavelength division multiplexing(WDM)CSPE secure communication sytem is proposed,to confirm the compatibility of the proposed CSPE communication system with traditional optical transmission technology.The influencs of the channel spacing,transmission rate and transmission distance on the communication performances are investigated.On the basis of achievement of point-to-point CSPE secure communication system,the CSPE communication networks with star topology and ring topology are proposed,which extend the point-point secure communication to the scenarios of point-to-multipoint and multipoint-to-multipoint communications.It is demonstrated that under the conditions of 40Gbit/s and 50 km transmission,broadcast communications from the centralized node to star nodes can be achieved in the star-toplogy network,and the bidirectional secure message exchange between adjacent nodes can be implemented in the ring-topology network.These results confirm the application feasibility of the CSPE in the high-speed chaotic secure communication networks.