A novel QKD network routing algorithm based on optical-path-switching

The hybrid model of QKD(Quantum Key Distribution) network is a reasonable approach to build a quantum cryptographic network in the current phase which combines the optical switcher and the trusted repeater to attain the security and the scope of the network. The core network of this model is connected and routed by optical switchers, and is extended in spacial scale by the trusted repeater. This paper focuses on the routing method in the core network. Since the quantum path established by the optical switchers is monopolized by the current pair of Alice and Bob, the routing algorithm of the conventional network couldn't deal with such a dynamic graph. More factors would be considered to find and keep an optical path in a dynamic graph. Based on a cost function of the optical path define in this paper, an multi-path search algorithm is proposed to find available optical paths and select a best path as the route of one process of key distribution. Experiments raised on NS2 demonstrates the validity and effectiveness of the proposed algorithm.