Markov Chain Trust Model for Trust-Value Analysis and Key Management in Distributed Multicast MANETs

To increase efficiency in mobile ad hoc networks (MANETs), the multicast MANET is proposed for a sender that sends packets to several receivers through a multicast session. In MANETs, multicast group members frequently change due to node mobility; thus, supporting secure authentication and authorization in a multicast MANET is more critical than that in a wired network with a centralized certificate authentication (CA) server. This paper thus proposes a two-step secure authentication approach for multicast MANETs. First, a Markov chain trust model is proposed to determine the trust value (TV) for each one-hop neighbor. A node's TV is analyzed from its previous trust manner that was performed in this group. The proposed trust model is proven as an ergodic continuous-time Markov chain model. Second, the node with the highest TV in a group will be selected as the CA server. To increase reliability, the node with the second highest TV will be selected as the backup CA server that will take over CA when CA fails. The procedures of the secure authentication for group management are detailed. The security analysis of each procedure is analyzed to guarantee that the proposed approach achieves a secure reliable authentication in multicast MANETs. In addition, several famous attacks have been analyzed and discussed. Numerical results indicate that the analytical TV of each mobile node is very close to that of simulation under various situations. The speed of the convergence of the analytical TV shows that the analyzed result is independent of initial values and trust classes. This is a good feature of analytical models.