**6. Conclusion**

The problem of secure routing in WSN is an important area of research that has various aspects of considerations. One important direction under this area is to provide security mechanisms against behavioral related attacks. In this chapter, a comprehensive treatment of the Reputation system based Trust-Enabled Routing framework for wireless sensor networks is provided. We have highlighted the importance of Trust-Aware Routing considering the different network aspects and special conditions of WSN. We have provided a comprehensive review and an in-depth discussion of different Reputation system based Trust-Aware routing approaches highlighting their pros and cons. In our proposed work, we investigated reputation based systems as a promising solution for behavioral related routing security problems. The work developed a new reputation system called SNARE (Sensor Node Attached Reputation Evaluator)[82] that is designed to meet WSN conditions and constraints. This system is divided into three components; i.e. monitoring, rating and response components. Each component is designed with the features that make it possible to apply and then optimize for WSN applications and conditions. In the response component, an enhanced trust aware routing protocol was proposed, called GETAR(Geographic, Energy & Trust Aware Routing). Simulation results showed that this enhanced protocol performs well in terms of increasing packet delivery ratio with tradeoffs in terms of energy balancing. Energy balancing raises an issue of optimization, as well.

As future work, some of the interesting issues to be analyzed to build a robust reputation system are - accurate and efficient trust/reputation modeling and management specific to Wireless Sensor Networks environments, performance of the examined cooperation enforcement with respect to network throughput realized, communication overhead introduced, time required for obtaining accurate reputation ratings/detecting misbehaving nodes, robustness against spurious ratings under a common reference scenario.
