Securing the Scalable Source Routing Protocol

The Scalable Source Routing (SSR) protocol combines overlay-like routing in a virtual network structure with source routing in the physical network to a single cross-layer architecture. Thereby, it can provide indirect routing in networks that lack a well-crafted structure. SSR is well suited for mobile ad hoc networks, sensor-actuator networks, and especially for mesh networks. Moreover, SSR directly provides the routing semantics of a structured routing overlay, making it an efficient basis for the scalable implementation of fully decentralized applications. In this paper we analyze SSR with regard to security: We show where SSR is prone to attacks, and we describe protocol modifications that make SSR robust in the presence of malicious nodes. The core idea is to introduce cryptographic certificates that allow nodes to discover forged protocol messages. We evaluate our proposed modifications by means of simulations, and thus demonstrate that they are both effective and efficient.