Research On Security Key Distribution Based On Chaotic Synchronization

With the development of information and communication technology,the security of information has received more and more attention.Ensuring and improving the security of information system has become an important strategic problem of concern to all countries in the world.In the secure communication system,the safe and effective distribution of shared key for both parties is the crucial aspect to ensuring information security,thus,secure key distribution has become one of the hot research topics in the secure communication field.Recently,most of the key distribution schemes are mainly based on deterministic algorithms,so the generated keys are pseudo-random.With the development of high-speed computer technology,the security of algorithm-based key distribution technology is severely challenged.On the other hand,the quantum key distribution technology with theoretical absolute security also faces many application problems that need to be solved because of the low key generation rate(currently only Mbps),unfavorable transmission distance and high device requirements.Therefore,it has important theoretical and practical application value to explore the secure key distribution schemes with high-security,high-rate and easy realization.Based on the frontier research situation of key distribution technology,this thesis combines laser chaos synchronization and physical random number generation technology to develop a high-speed key distribution technology based on chaotic synchronization,proposes the key distribution schemes and studies the feasibility and performance of each scheme.The specific research works are as follows:Firstly,the theoretical model of semiconductor laser is introduced.The synchronization mechanism and synchronization conditions of laser chaos synchronization are studied,and a key distribution scheme based on laser chaos synchronization is constructed.Secondly,we propose two secure key distribution schemes based on the dynamic chaos synchronization and alternating step algorithm.By exchange the random control parameter,the communication parties can identify the time slots in which high-quality chaos synchronization is achieved.The difference between two schemes is that the parameters controlled by the random control parameter are different.One is that the injection strengths are dynamically controlled by the random control parameters,and the other one is that the feedback delays of the local external-cavity semiconductor lasers are dynamically controlled by the random control parameters.Based on this,a binary sequence can be independently generated by Alice and Bob as a seed key,in virtue of post-processing.Then,the rate of the seed key can be extended by using iterative alternating step algorithm,and the high-speed key distribution can be achieved.The numerical simulation results shows that the high-quality chaos synchronization can be achieve between Alice and Bob,and the key distribution with a rate much higher than that of the seed key can be achieved,the final key can be enhanced by 21 times that of its seed key.In the improved scheme,the control sequences of the iterative alternating step algorithm are changed by delay operation,and the simulation results show that the final key rate can be enhanced by 98 times that of the seed key.Finally,the secure key distribution scheme based on the parallel semiconductor laser system.The chaos synchronization of this scheme is achieved by using the structure of the parallel semiconductor lasers,and then the key distribution can be achieved.Based on this,an optimization scheme is proposed,which is the secure key distribution scheme based on the phase-modulated parallel semiconductor laser system,that is,there is a phase modulator in the feedback loop of each external cavity semiconductor laser.The simulation results show that the high-quality chaos synchronization can be achieved,and the high-rate secure key distribution can be performed.