Secure and reliable broadcasting in wireless sensor networks using multi-parent trees

Wireless sensor networks (WSNs) have been the focal point of research over the last several years. Broadcast communication is a key requirement for WSNs since many tasks in the network depend on broadcasting, including critical tasks like querying. Consequently, securing broadcast communication over sensor networks has become an important research challenge. Typically, broadcast communication involves two steps: broadcasting and acknowledging. In the broadcasting phase, the message is broadcast in the network. In the acknowledging phase, nodes that successfully received the broadcast message send an acknowledgment to the broadcast origination node, which in this paper is always the sink. The terms ‘sink’ and ‘base station (BS)’ are used interchangeably throughout this paper. Intuitively, broadcast communication has two important metrics: reliability and security. Though the reliability metric has drawn sufficient attention in the research community, the security metric has not. In this paper, we address both metrics with an emphasis on the former and address the Denial-of-Broadcast Message attacks (DoBM) in sensor networks. We propose a novel multi-parent tree-based model called the k-Parent Flooding Tree Model (k-FTM). We also present distributed algorithms for the construction of k-FTM and prove via simulation and analysis that the proposed k-FTM is robust against DoBM. Our Multi-Parent tree model enables the BS to detect DoBMvery efficiently, even in the presence of a prudent adversary who focuses on remaining undetected by causing damage below the detection threshold. k-FTM is, to our best knowledge, the first fault-tolerant tree model that is both reliable and secure. Through simulations we confirm that our model achieves detection rates close to that of a static tree and a broadcast reliability close to that of blind flooding. Copyright © 2008 John Wiley & Sons, Ltd.