Trust-based Security Research In Wireless Sensor Networks

There are more and more network security problems occurring in wireless sensor networks because of the resource-constrained sensor nodes and the poor surroundings. As regards the fact that the encryption-based method could avoid the exterior attacks but couldn't resolve the internal attacks which occur when nodes are captured, while the trust mechanism designed to resolve the interior attacks could distinguish captured nodes from networks timely. This thesis aims to combine the two methods into an integrated program. Meanwhile, the current trust mechanism pays more attention to the frame designing than monitoring modules. So it has many problems, such as higher energy consumption and low QoS and so on. Therefore, this thesis also attempts to find the way to reduce the energy consumption at the basis of good quality of the trust mechanism.Followed are the queries presented and to be resolved in this thesis.1. At first, the thesis gave a simple description of the Wireless Sensor Networks structure, the arrangement of sensor node, and the differences from traditional network figures. Then, it conducts an analysis and summary about the security menace and protection schedule. Based on the investigations it presents the basic goal of network security under the given environment which should be taken into consideration.2. The trust-based dynamic encryption program was proposed to settle the problems of collusion existed in the Wireless Sensor Networks dynamic encryption distribution scheme. It introduces trust mechanism into the process of dynamic encryption management and monitors the captured nodes initiative ly according to trust value of the nodes so that extrudes the unsafe captured nodes from network encryption security system timely. In emulation, the program succeeds to solve the problem of collusion.3. Analyzing the QoS of the available trust-management program and pointing out that there still was large room for improvements in energy consumption, expandability, communication load and calculation complexity. Based on the analysis, it put forward an efficient trust management project which not only could obtain the data of the nodes'action via the random monitoring mechanism of nodes as well as compose and update trust data according to the current trust value of each node, and also could employ the trust data in the process of choosing GEAR route. In emulation, besides assuring the security of trust management, this scheme reduces the energy consumption of the whole system.