A trust model based routing protocol for secure ad hoc networks

Security issues have been emphasized when mobile ad hoc networks (MANETs) are employed into military and aerospace fields. We design a novel secure routing protocol for MANETs. This protocol TAODV (Trusted AODV) extends the widely used AODV (ad hoc on-demand distance vector) routing protocol and employs the idea of a trust model to protect routing behaviors in the network layer of MANETs. In the TAODV, trust among nodes is represented by opinion, which is an item derived from subjective logic. The opinions are dynamic and updated frequently as our protocol specification: if one node performs normal communications, its opinion from other nodes´ points of view can be increased; otherwise, if one node performs some malicious behaviors, it is ultimately denied by the whole network. A trust recommendation mechanism is also designed to exchange trust information among nodes. The salient feature of TAODV is that, using trust relationships among nodes, there is no need for a node to request and verify certificates all the time. This greatly reduces the computation overheads. Meanwhile, with neighbors´ trust recommendations, a node can make objective judgement about another node´s trustworthiness to maintain the whole system at a certain security level.