Abstract— Securing broadcast communication over sensor networks is an important research challenge. In general, broadcast communication has two important metrics: security and reliability. Though the reliability metric has drawn sufficient attention in the research community, the security metric has failed to do so. In this paper we address both these metrics with more emphasis on the former and address the Denial-of-Broadcast Message attacks (DoBM) in sensor networks. We propose a tree based model called the k-parent Flooding Tree Model (kFTM) and present algorithms for the construction of k-FTM. The proposed k-FTM is robust against DoBM and enables the base station to detect DoBM very 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 secure and reliable. We confirm through simulations that our model achieve...