A Two-Way Trust Assurance of Aggregator Node for Ensuring Data Reliability in Wireless Sensor Networks

Wireless Sensor Networks (WSNs) consists of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, and to cooperatively pass their data through the network to a base station. Data Fusion/Aggregation can effectively reduce the volume of data transmission in the network, reduce the energy consumption to extend network lifetime and improve bandwidth utilization, as a result, it can overcome the restriction of energy and bandwidth. Moreover since a sensor is typically placed in locations that are accessible to malicious attackers, information assurance of the data fusion process is very important. In order to improve the performance in terms of assurance, overhead and delay, we proposed a novel trust based direct voting mechanism [1]. Our work employs trust metric to poll the witness nodes for in the process of data fusion assurance. In this paper we extended the work of [1] in terms of bottom-up approach where the child node can select the node (parent) to forward the data. Generally, a hierarchical data collection scheme is used by the sensors to report data to the base station, it is difficult to precisely identify and eliminate a compromised node in such a data collecting hierarchy. Most security schemes for sensor networks focuses on developing mechanism for nodes located higher in the hierarchy to monitor those located at lower levels. We propose a complementary mechanism with which the nodes at lower levels can monitor their parents in the hierarchy to identify the behavior, based on that child will select the parent node to forward the data. Every node maintains a reputation (trust) value of its parent and updates this at the end of every data reporting cycle. We propose a novel combination of statistical testing techniques and reinforcement learning schemes to manage the reputation of a parent node. In this paper baye’s theorem is used to evaluate the trust of nodes. The performance of proposed approach is evaluated and compared with previous approaches and found that our approach has a lower overhead than the previous approaches in terms of delay and energy consumption.