Research On Trust Management Mechanisms In Wireless Sensor Networks

With the development of information technologies and the expansion of network applica-tion requirements, a wireless sensor network has been focused on by industry and research fields more and more. Many technologies are applied in wireless sensor networks, including network support technology, service support technology and application support technology. A wireless sensor network is a highly distributed network, which is deployed using a large number of sensor nodes in harsh environments. Due to inherent vulnerabilities of easily suffering from external and internal attacks via a variety of methods, including eavesdropping, fabrication, modification of packets, clones of nodes and so on. The security issue is a critical problem in wireless sensor networks. As the effective supplement of traditional security technologies,"trust" has been put forward to apply in deferent networks. A trust scheme in wireless sensor networks has been gradually studied by current researchers and remains an open and challenging field.We categorize the various types of attacks and countermeasures related to trust schemes, give a short summarization of classical trust methodologies, emphasize the challenges of trust scheme in wireless sensor network, and analyze the state-of-the-art trust mechanisms in wireless sensor networks. Considering the characteristics of wireless sensor networks, we provide several trust models in wireless sensor networks. The contributions of the dissertation are listed as follows:(1) In order to deal with the problems of energy consumption and fairness of trust eval-uation in wireless sensor networks, a Rasch-based management trust scheme is proposed. By introducing the Fitness Degree of a sensor node, which is used for judging the relationship be-tween the node latent ability and the task difficulty, our proposed model can rationally enhance the fairness of trust evaluation and save energy of sensor nodes. It is the first trust scheme that measure the fairness of trust in wireless sensor networks. Experimental results show that this scheme effectively distinguishes malicious nodes, increases the utilization rate of individual nodes, and prolongs the lifetime of wireless sensor networks.(2) A novel trust management model based on the subjective logic trust is proposed for service-oriented distributed networks. The proposed algorithm involves passive trust of enti-ty and combines the direct trust and recommendation trust. We also propose a novel scheme called passive trust feedback to avoid the deceit of malicious nodes and unstable nodes, and to encourage honest nodes. Our proposed model expands the trust range of service resource via passive trust of entity, which generates a flexible access path to the service resources. Simula-tions show that the proposed trust management model can significantly improve the feasibility of trust management as well as effectively detect malicious entities.(3) A new trust-based securing data aggregation model is proposed to deal with the security issue of data aggregation in wireless sensor networks. To verify the correctness of integrity of sensing data and aggregation results, we can obtain the behavior records of each aggregator and children nodes. The base station will collect all behavior records of nodes and calculate trust values, and then build the candidate representation node list and aggregator node list via the trust value and residual battery. Simulations show that the proposed approach can identify malicious nodes immediately and decrease the energy consumption of network compared with other approach.