Research On Distributed Routing Mechanism Of Quantum Key Distribution Network

With the continuous development of quantum key distribution technology,a quantum key distribution network that can realize multi-user and long-distance key distribution has attracted widespread attention.In trust relaying quantum key distribution network,the combination of quantum key distribution technology and "one-time pad " can realize the key distribution of information-theoretic security.With the expansion of quantum key distribution network scale,it is necessary to connect multiple point-to-point quantum key distribution systems to realize end-to-end key distribution.How to make routing is one of the problems that must be solved.A reasonable routing algorithm can improve the key utilization,balance network resources,and improve network performance.At the same time,a reasonable routing strategy can also improve the network security.This paper mainly discuss the distributed routing mechanism based on trusted relay quantum key distribution network from three aspects: routing protocol,routing algorithm and routing strategy.Most of the routing protocols used in quantum key distribution networks are improved on the basis of the OSPF protocol.When calculating the link cost,the core factors that are mainly considered are the amount of remaining link keys,the link key generation rate,the capacity of the key pool and routing hops.The existing routing algorithms basically consider the amount of remaining link keys.If you want to reduce the consumption of link key,you can consider routing hops.If you want to balance the network resources,you can consider of the link key generation rate.Common routing strategies include random routing strategies and multi-path routing strategies.Multi-path routing strategies are more secure than random routing strategies,but consume more link keys.On the basis of the above research,two routing schemes based on trusted relay quantum key distribution network are proposed.1.The multi-path routing scheme based on trusted relay quantum key distribution network is improved,and the least common node multi-path routing scheme is proposed.When selecting multiple paths,this scheme uses the improved Dijkstra algorithm to find all the optimal paths.At the same time,a marking strategy is used to select disjoint paths among all the optimal paths to avoid the reduction of the communication key relay security caused by the selection of public nodes.Compared with the random routing scheme,the least common node multi-path routing scheme improves the security of communication key relay.Compared with the multi-path routing scheme,the least common node multi-path routing scheme not only ensures the security,but also reduces the consumption of link key.2.In order to use each QKD link in a balanced way when the communication key is relayed,and balance the network resources,a routing scheme with the least repeated links is proposed.This scheme first determines the initial link cost of each QKD link according to the amount of remaining link keys,key pool capacity and link key generation rate.In order to avoid repeated selection of certain links,the conflict cost of the link is calculated according to the number of occurrences for the link that may appear repeatedly(ie,the critical link),then recalculate the link cost of the critical link through the initial link cost and the conflict cost.Finally,the final routing path is calculated by Dijkstra algorithm according to the new link cost.The experimental results show that the least repeated link routing scheme can use each link more balanced,and improve the success rate of communication key relay,compared with the scheme that only selects the route based on the initial link cost.