Abstract: A wireless sensor network (WSN) is a large collection sensor node with limited memory, battery and processing capacity. Due to this limited resources the energy conservation plays important role in wireless sensor networks. We formulate optimization problem for dynamically determining the best redundancy level to apply to multipath routing for intrusion tolerance so that query success probability maximized while prolonging system useful lifetime. In redundancy management “packet dropping” and “Bad mouthing” are the major problems in managing the redundancy. In order sort out these problems we plan to propose “weighted voting” based trust management method is used to achieve best energy efficiency. The main function of weighted voting method is to find the trust/reputation of neighbor nodes.