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Abstract-As wireless sensor networks are characterized by severely constrained node resources, low communication range, low memory capacity and dynamic nature of WSNs, implementing security functionality and detection protocols to protect against adversary nodes becomes a challenging task. It is very likely that the encryption keys in the sensor nodes are accessed by attacker entities. The compromised nodes can launch sinkhole or wormhole attack to prevent the arrival of important information to the base station (BS). Establishing trust among distributed network entities has been recognized as a powerful tool to secure distributed networks such as MANETs and sensor networks. In this paper we first estimate the area in the network where a sinkhole attack has occurred there by considering the energy consumption model in the network. Then we present an entropy-based trust model in which more factors that affect trust computation are introduced. We apply a trust-based routing for providing a high level of security by path selection based on packet trust requirement. So it is needed that a routing protocol classifies the traffic packets according to their requested security and then routs the packets related to each class through the path that fulfills the security requirements of them. Our proposed approach that purposes to cover the mentioned problem is a resource efficient security protocol. This means that a trust value is allocated to the area suspected of sinkhole; the area is located by analyzing the energy of networks nodes and the packet is forwarded through low risk paths.Index Terms-Wireless sensor networks, sinkhole attack, trust model, secure routing.
I. INTRODUCTIONIn sinkhole attack the compromised node attracts the traffic of its neighbors by pretending that it has the shortest path to the base-station.and drops them. So it prevents the BS to receive sensed information completely and correctly. The sinkhole may launch a variety of attacks against the data traffic. If the sinkhole node drops the packets selectively we are facing a selective forwarding attack. Also it may modify some packets content and forwards them which is the most malicious type of sinkhole [1], [2]. Compromised nodes in selective forwarding attack are modeled as nodes that drop messages with probability p messages instead of forwarding them. When the probability p=1 we are facing sinkhole nodes [3]. In order to protect WSNs against malicious and selfish behavior, different secure routing protocols have been Manuscript received April 3, 2014; revised June 13, 2014. Omid Naderi and Mehdi Shahedi are with the Department of Computer, Science and Research Branch, Islamic Azad University, South Khorasan, Birjand, MhdShahedi@Gmail.com).Sayyed majid Mazinani is with the Electrical Engineering Department, Imam Reza International University, Mashhad, Iran (e-mail: smajid_mizinani@yahoo.com).developed which mainly rely on cryptographic Basics and authentication mechanisms which are not suitable for WSNs. It is difficult to prevent pack...