In current network routing domain, routing information lacks protection based on confidentiality. This makes network routing vulnerable to many types of security attacks. In this paper, we present a framework to provide confidentiality for link state routing protocol. This framework involves creation of a trust structure among routers and key management. The routing information is encrypted, so that it can be accessed only by authorized routers. We present an implementation framework for our approach by extending Open Shortest Path First (OSPF) intra-domain routing protocol. Based on our performance assessment of the routers, we infer that the additional cost in implementing this scheme does not bring down the overall performance. I.