Improving security in Wireless Sensor Network using trust and metaheuristic algorithms

Wireless Sensor Network (WSN) through sensor nodes co-operation collect and send messages about a monitored environment to a sink. Structural health monitoring is an active area of research where structural integrity of civil structures is continuously monitored using wireless sensors. WSN's wide spread applications in various areas has opened the doors to vulnerabilities/security pitfalls. Security is of paramount concern for sensor network applications but implementation of cryptography / encryption techniques will increase the control overheads and also uses additional energy which is scarce. An emerging area of research to improve security is the implementation of trust mechanism which to a certain extent mitigates the pitfalls of regular security mechanism. Trust is important in wireless networks as collaboration/cooperation among nodes is critical to achieving system goals like routing reliability which is NP Hard. In this work a trust based Cluster Head selection mechanism using Firefly based metaheuristic is proposed to improve the security and network lifetime of the WSN. Firefly Algorithm (FA) is used as it handles combinational and numerical optimization multimodal problems efficiently. The proposed algorithm was evaluated using Mica testbed using 23 nodes and was also extensively simulated using MATLAB for large number of nodes to check the effectiveness of the proposed technique. Simulation results demonstrate the effectiveness of the proposed method for large number of nodes and the physical experimental setup shows performance improvement over LEACH.