Researches On Routing Algorithm In Integrated QKD Network Based On Trusted Relay Nodes

Quantum Key Distribution(QKD)technology can achieve unconditionally secure communication.Nowadays,the researches on QKD technology are mostly concentrated in dedicated QKD network.However,establishing a dedicated QKD network is too costly to popularize.So it is one of the most important thing to solve the problem of establishing a QKD network on the basis of the existing classical optical network.In this paper,to solve the problem of quantum key distribution and quantum encrypted communication in the integrated QKD network,in which quantum signal and classical signal transmit together,we did the following work:(1)We design an architecture of the node and a structure of the network.We divide the service nodes in the integrated network into classic service node and integrated service node.And we divide the network into encrypted data transmission layer and global key transmission layer.The two layers have independent routing tables,but routing protocol packets are all transmitted by the encrypted data transmission layer in order to save quantum keys.By the network architecture and node structure proposed in this paper,we can build an efficient,reliable and quantum key saving integrated network on the basis of classical optical network.(2)We propose a quantum key saving(QKS)routing algorithm.Based on the shortest path algorithm and using the local quantum key amount in the integrated service node as the metric,the QKS routing algorithm take the path with least service nodes among the top k shortest paths as the optimal path.Meanwhile,we take the influence of classic signals on quantum key generation into consideration.According to the result of the simulation,the QKS routing algorithm can save a lot of quantum keys in the integrated network when compared with the traditional shortest path algorithm.(3)We design a quantum key supply mechanism for the application layer of the integrated network.At first,we use a single-rate and single-bucket token bucket algorithm to limit the rate of application.Then we divide the traffic into high encryption level,common encryption level and low encryption level.Different levels of traffic go through different traffic shaping algorithm and then reach the quantum encryption interface.Proved by the result of simulation,this mechanism can reduce the chance of quantum encryption interface being congested and make integrated service node distribute quantum keys to multiple applications efficiently,fairly and controllably.