Design And Routing Optimization Of Quantum Cryptography Communication Network Based On SDN

With the development of the Internet,information security has attracted great attention.People have been studying various encryption schemes.However,with the development of supercomputers,encryption schemes that rely solely on complex computations are no longer safe.Quantum key distribution(QKD),based on the basic principles of quantum mechanics,combines with one time pad(OTP)strategy can ensure unconditional security of information transmission.For this reason,the quantum cryptography communication network is rapidly developing these years.In 2016,the successful launch of the first quantum science experiment satellite ”Mozi” has made the quantum cryptography communication networks enter the era of large-scale networking.In the quantum cryptography communication networks,as the expensive equipments and the strict requirement for the experimental environment,quantum key resources become very valuable.How to manage and control the key resources of the entire network has become an urgent problem that needs to be solved.In recent years,software defined network(SDN)is attracting people’s attention,and its core technology,OpenFlow,separates the network device control plane from the data plane,so it can enable flexible control of network traffic.Therefore,this thesis firstly fully takes advantage of SDN to propose a scheme of quantum cryptography communication networks based on SDN,and then researches on the dynamic routing algorithm.At First,this thesis introduces the development and research status of quantum cryptography communication networks and software defined networks.Secondly,some basic knowledge of quantum mechanics and QKD protocol are introduced.Then,the basic architecture of SDN and its key technology,OpenFlow,are introduced.There main contributions of this thesis are as follows:1.An architectural model based on SDN for quantum cryptography communication networks is designed.The four node models of controller,relay node,terminal node and Super controller node are designed and the according internal composition and working principle are described.The network model is realized through simulation and the information collection and monitoring of the relay nodes and terminal nodes are also achieved.The information exchange process between controller nodes and relay nodes are analyzed based on the packets captured by Wireshark.The analysis results show that the discovery and maintenance of links and key resources across the entire network have been successfully achieved based on SDN.2.Based on the previous work,this thesis also proposes a dynamic routing algorithm based on SDN that is suitable for quantum cryptography communication networks.This routing algorithm adopts the idea of Yen’s shortest path algorithm and it uses the hop count and the link key as the distance to the destination address.Finally,it overcomes the shortcomings of traditional routing algorithms that are not suitable for quantum cryptography communication networks.A more realistic network communication environment is obtained by the secondary development of the Mininet,and the dynamic routing algorithm is simulated in this enviroment.The experimental results prove the feasibility of the routing algorithm proposed in this thesis.Then the traffic of the relay nodes which are captured by sFlow are analyzed,and the result shows that the proposed routing algorithm is more suitable for the quantum cryptography communication network than the traditional RIP routing algorithm.Finally,we summarize the works,point out the deficiencies and also put forward the prospect of the following work.