Multi-channel Secure Communications Based On Optical Superchaos Systems And Complex Networks

With the advent of the information age, the secure issues of communication are more andmore regarded. The leak of important information (like military intelligence, financialinformation and individual privacy) maybe take place serious consequences. Therefore, theinvestigation about information secure becomes a comprehensive attention issue, which alsois of important significance.In this thesis, the main works are:First, the importance, as well as the basic principles of secure communication areintroduced briefly, the characteristics and synchronization principles of chaos systems aresummarized and analyzed, and the techniques to realize secure communication based onchaos synchronization are sumed up emphaticly. At last, the current status and progress ofinvestigation about secure communication are expounded.Second, secure communication with multi-channel signals is investigated suinghyperchaos systems with topological isomerism of dual-ring Er-doped fiber laser andmulti-mode Nd:YAG laser with the frequency doubling crystal in cavity. The chaoticcharacteristics of the two hyperchaos systems are analyzed. And the basic principle of securecommunication between hyperchaos systems loaded multi-channel signals is studiedtheoretically, and the synchronization controllers and the signal update rules are designed byusing the methods of parameter modulation and adaptive synchronization. The results ofnumerical simulation show that the transmission of multi-channel secure information betweenoptical hyperchaos systems with topological isomerism, i.e. dual-ring Er-doped fiber laser andmulti-mode Nd:YAG laser, is realized. The secure information is demodulated and recognizedwithout distortion at sink. At the same time, it is proved that the respond time is not concernedwith the number of channel (1~3), the type of signal (analog or digital) and parameters ofsignal (different frequency or amplitude)Third,2N-dual-ring erbium-doped fiber lasers are selected as nodes of two star networksand every node at launch network is loaded multi-channel secure information. The securecommunication between complex networks is researched theoretically and numerically. Theresults show that the coupling and linking between nodes within different star network can berandom, and each node in launch network can transmit multi-channel secure informationsynchronously. Especially, every node in the receiver network will secure information withoutdistortion, which improves efficiency of information transmission.Finally, N-dual-ring erbium-doped fiber lasers and N-multi-mode Nd:YAG laser with the frequency doubling crystal in cavity are chosen as nodes to construct two star networks withsame structure. The type of hyperchaos is the same in respective network. However, the typeof hyperchaos is the different in different network. The transmission characteristics ofmulti-channel secure signals between the star networks are investigated. The new controllersfor network synchronization and the signal update rules for secure communication are given.Further, the multi-channel secure communication is realized between star networks with samestructure but different node of hyperchaos systems in respective network.