Recently, multi-hop wireless mesh network (WMN) has attracted increasing attention and deployment as a low-cost approach to provide last-mile broadband Internet access [4]. However, to further widen the deployment of WMN, privacy issue must be addressed. For example, in a community mesh network, the traffic of a residence can be observed by the mesh routers residing at its neighbors, which could reveal sensitive personal information. Despite the necessity, limited research has been conducted towards privacy preservation inWMN. This motivates us to investigate the privacy preserving mechanism in WMN.