Abstract-Secure communication is one of the most critical challenging tasks in multi-hop Wireless Sensor Networks (WSNs). Routing protocols of WSNs are highly susceptible to various attacks, which replay the routing information through the malicious node and steal the identities of the valid nodes in a network. The malicious nodes forward the packets far away from the sink, increasing the packet drop ratio, that sluggishes overall network efficiency. In order to overcome this problem, we have designed and implemented a secure trust aware energy efficient adaptive routing (STEAR) for dynamic WSNs. This protocol provides secure, trustworthy and energy efficient routing for multihop networks. STEAR is designed with effective mechanisms to identify the malicious nodes using dynamic secret key (DSK) assignment, trust and energy monitoring, and packets flow status monitoring. Simulation results show that network efficiency and throughput are better and packet drop ratio is reduced compared to earlier works.Index Terms-Dynamic secret key (DSK), energy monitor, secure communication, trust monitor, WSNs.
I. INTRODUCTIONTo achieve trust aware routing in multihop environment in WSNs is one of the most challenging tasks. The malicious nodes divert the messages far away from the sink, create congestion and disrupt the communication channels through different overwhelming attacks [1]. Major attacks that affect the multi-hop routing are Sybil attack, Worm Hole attack and Sink Hole attack [2].The effect of these three attacks brings down the network efficiency in both static and mobile sink environments. The impact of these attacks is more in mobile sink environments when compared to static sink networks [3]. These attacks may also cause irreparable damage to the minimum security levels in networks.
A. MotivationSecurity is one of the important issues in WSNs. Secure communication in WSN improves network efficiency and throughput. In earlier works, trust and status supervision schemes consider the trust value and energy level of each node while transferring the data from the source to the sink. Bangalore, shaila_ks@yahoo.com, venugopalkr@gmail.com).V. Tejaswi is with the NIT, Suratkal, India (e-mail: tejaswikrv@gmail.com).L. M. Patnaik is with the Indian Institute of Science, Bangalore, India (e-mail: lalitbr@gmail.com).The attackers are still successful to replay the routing information to extract the valid identity. Thus, it is necessary to device a mechanism by considering dynamic secret key (DSK), packet flow status along with trust and energy requirement level to improve the network security, efficiency and throughput. These parameters are illustrated by using an example as shown in Fig. 1. Assume that an event has been generated at node A, then it begins to find a valid neighbour node to forward the packets towards the sink through one of its neighbours such as X, Y, E and C. The routing table of every node maintains the information like the trust level, the energy requirement to drive the packets towards sink, packet fl...