Research On Time Synchronization Mechanism Of Quantum Key Distribution Optical Networks

Nowadays,with more and more confidential and sensitive information in key fields such as government,military and finance transmitted through optical network,the security threat of optical network has attracted more and more attention.Based on the information theory and the laws of quantum physics,quantum key distribution can unconditionally share key security between remote parties.It is considered to be a promising solution to ensure the security of optical networks.With the rapid development of quantum key distribution technology,quantum key distribution network integrating quantum key distribution technology and optical network has become the research focus of future development.With the close combination of quantum key distribution technology and traditional Ethernet,the proposal of quantum backbone network integrating various key distribution protocols and the increasing application of quantum key encryption,in order to ensure the accuracy and real-time of data and key interaction in the network,the time synchronization technology based on network level will play a fundamental role in the construction of multi-point interconnected quantum key distribution network.Focusing on the time synchronization mechanism of quantum key distribution network,this paper focuses on the three perspectives of"synchronous network architecture,synchronous network delay optimization and synchronous network routing survivability".Aiming at the three core challenges of "low delay networking construction,adaptive synchronous routing selection and synchronous network routing protection" in the time synchronization mechanism of quantum key distribution network,based on the traditional time synchronization technology and combined with the characteristics of quantum key distribution network,It mainly completed three technical innovations:time synchronization architecture of distributed cooperative quantum key distribution network,node adaptive time synchronization scheme for multi time domain,and synchronous routing protection strategy based on quantum key pool tolerance,which provided theoretical support for the scalability,high accuracy and low delay applications of quantum key distribution network.The main innovative work and research results of this paper are as follows:(1)Technical challenges from the perspective of "synchronous network architecture":how to design the synchronization architecture and networking strategy of quantum key distribution network,so as to provide a highly adaptive time synchronization architecture and reduce the global delay of the network?A distributed cooperative time synchronization architecture of quantum key distribution network is proposed.By combining the characteristics of quantum key distribution light-emitting network architecture and traditional optical network time synchronization architecture,based on the quantum key distribution lightemitting network architecture,the network element attributes such as time synchronization backbone nodes and sub nodes in time domain are introduced,the functions of time synchronization network are layered,and the specific structure and functions of each layer are defined.On this basis,a backbone node selection algorithm and a resource balanced network layered and domain strategy are proposed.The simulation is compared with the traditional master-slave time synchronization network architecture in many indexes,such as the maximum delay of neighbor nodes,the maximum delay of global network nodes,synchronization accuracy and so on.The simulation results show that under the synchronous simulation environment set in this paper,in the simulation network based on NSFNET,the global delay of distributed collaboration is reduced by 564.27us compared with the master-slave architecture,which verifies the delay accuracy and effectiveness of the proposed synchronization architecture.(2)For the technical challenge from the perspective of"synchronization delay optimization":how to optimize the time synchronization path selection and delay calculation to reduce the endto-end delay and error of the network?A node adaptive time synchronization scheme for multi time domain is proposed.Considering the different node attributes of quantum key distribution network,the accuracy requirements of network nodes and service time synchronization,the scheme integrates the key distribution service and time synchronization service,and designs two adaptive time synchronization routing sub algorithms based on intra domain and inter domain node attributes based on node attributes and service bearer.Through simulation,the end-to-end node delay,synchronization accuracy,synchronization resource consumption and service success rate in the network are comprehensively evaluated.The simulation results show that compared with the non node adaptive traditional synchronization scheme,under the simulation environment set in this paper,the node adaptive time synchronization scheme effectively reduces the routing delay of 306.42us compared with the traditional synchronization scheme,and improves the service success rate by 12.9%under various service accuracy threshold conditions.(3)For the technical challenge from the perspective of"synchronous network routing survivability":how to provide efficient link synchronization accuracy detection and multi-path routing protection to improve the success rate of key distribution in low precision synchronous network environment?A synchronous routing protection strategy based on quantum key pool tolerance is proposed.By analyzing the source of precision decline and the time-varying problem of key resource generation and consumption in quantum key distribution network,the change of key resource and time delay difference with time are coupled and modeled,and a security capacity model based on key pool is constructed.On this basis,a routing resource allocation algorithm based on multipath is proposed.Simulation results show that the proposed algorithm comprehensively improves the service success rate of 11.3%and the key resource utilization rate of 10.5%on the basis of meeting the requirements of service delay accuracy.