DH-based communication method for cluster-based ad hoc networks

Engineers have proposed lots of mechanisms for providing secure communications in ad hoc networks since the early 1990s. Due to the absence of fixed infrastructure, ad hoc networks are more vulnerable when encountering security threats than conventional wireless networks. The mobile ad hoc network can be considered as a short-lived collection of mobile nodes that communicate with each other. All involved nodes in the network system share the responsibility for routing, access and communication. Namely, ad hoc networks are self-configurable networks with dynamic topologies. The main constraints on the design of mobile ad hoc networks include high power saving and low bandwidth. The public key infrastructure (PKI) is a well-known scheme used to ensure secure communications in mobile ad hoc networks. Based on PKI cryptosystems, Varadharajan et al. proposed a secure communication scheme in cluster-based ad hoc networks in 2004. However, with deep insight into Varadharajan et al.´s scheme, the computation loads of PKI become the heavy burden to each communicating member in the cluster. In this article, we propose a Diffie-Hellman (DH)-based scheme for providing confidential communications in ad hoc networks without adopting PKI cryptosystems. Furthermore, our scheme can preserve the forward secrecy and the backward secrecy of a group communication