CSR: Classified Source Routing in Distributed Networks

In recent years cloud computing provides a new way to address the constraints of limited energy, capabilities, and resources. Distributed hash table (DHT) based distributed networks have become increasingly important for efficient communication in large-scale cloud systems. Previous studies mainly focus on improving the performance such as latency, scalability and robustness, but seldom consider the security demands on the routing paths, for example, bypassing untrusted intermediate nodes. Inspired by Internet source routing, in which the source nodes specify the routing paths taken by their packets, this paper presents CSR, a tag-based, Classified Source Routing scheme in distributed networks to satisfy the security demands on the routing paths. Different from Internet source routing which requires some map of the overall network, CSR operates in a distributed manner where nodes with certain security level are tagged with a label and routing messages requiring that level of security are forwarded only to the qualified next-hops. We show how this can be achieved efficiently, by simple extensions of the traditional routing structures, and safely, so that the routing is uniformly convergent. The effectiveness of our proposals is demonstrated through theoretical analysis and extensive simulations.