A fuzzy trust management mechanism with dynamic behavior monitoring for wireless sensor networks

Traditional wireless sensor networks (WSNs) are typically deployed in remote and hostile environments for information collection. The wireless communication methods adopted by sensor nodes may make the network highly vulnerable to various attacks. Traditional encryption and authentication mechanisms cannot prevent attacks launched by internal malicious nodes. The trust-based security mechanism is usually adopted to solve this problem in WSNs. However, the behavioral evidence used for trust estimation presents some uncertainties due to the open wireless medium and the inexpensive sensor nodes. Moreover, how to efficiently collect behavioral evidences are rarely discussed. To address these issues, in this paper, we present a trust management mechanism based on fuzzy logic and a cloud model. First, a type-II fuzzy logic system is used to preprocess the behavioral evidences and alleviate uncertainty. Then, the cloud model is introduced to estimate the trust values for sensor nodes. Finally, a dynamic behavior monitoring protocol is proposed to provide a balance between energy conservation and safety assurance. Simulation results demonstrate that our trust management mechanism can effectively protect the network from internal malicious attacks while enhancing the energy efficiency of behavior monitoring.