Secure Link State Routing Protocol: A Framework for Network Survivability

Network survivability has been studied extensively from the view of node and link failures. The domain of survivability goes beyond just the physical failures and one needs to address this issue when faced with security threats that can render the network logically dysfunctional without causing any physical damage. There are several security threats a network routing protocol such as the linkstate protocol may face. In this paper, we argue that this leaves network routing and, in turn, network susceptible to a number of attacks. We discuss these attacks and present a new secure routing framework based on security techniques (authentication and confidentiality) for a link state routing protocol. The central idea of the new framework is to divide a routing domain into multiple virtual routing domains and creating a hierarchical trust among them to address the survivability issue of the network. We illustrate that imbedding this framework to an existing protocol can be done without major modifications to the existing protocol, and without affecting its operational features. Our assessment shows that the framework is capable of preventing many currently unchecked security threats without unduly overloading routing elements in routers. Our framework also provides survivable capability for the subset of functional network routers in the event of formidable attacks like the insider attack.