Trust based routing mechanism for securing OSLR-based MANET

A mobile ad hoc network (MANET) is a kind of infrastructure-less wireless network that is self-organized by mobile nodes communicating with each other freely and dynamically. MANET can be applied to many fields, such as emergency communications after disaster, intelligent transportation, and Internet of things. With the rapid development of wireless network applications, MANET will become dense and large because more and more mobile devices are required to be interconnected. The optimized link state routing (OLSR) protocol is an efficient proactive routing protocol which is very suitable for such dense and large-scale MANET. However, in both data plane and routing plane, OLSR-based MANET suffers from many serious security threats which are difficult to resist via traditional security mechanisms. In this paper, we propose a trust based routing mechanism to alleviate this issue. In this mechanism, a trust reasoning model based on fuzzy Petri net is presented to evaluate trust values of mobile nodes. In addition, to avoid malicious or compromised nodes, a trust based routing algorithm is proposed to select a path with the maximum path trust value among all possible paths. Then we extend OLSR by using the proposed trust model and trust based routing algorithm, called FPNT-OLSR. For the implementation of FPNT-OLSR, we design a trust factor collecting method and an efficient trust information propagating method, which do not generate extra control messages. Simulation results show that FPNT-OLSR is very effective in establishing secure routes. It also performs better than existing trust based OLSR protocols in terms of packet delivery ratio, average latency and overhead.