Modeling Secure Connectivity of Self-Organized Wireless Ad Hoc Networks

Wireless ad hoc networks (WANETs) offer communications over a shared wireless channel without any pre-existing infrastructure. Forming peer-to-peer security associations in self-organized WANETs is more challenging than in conventional networks due to the lack of central authorities. In this paper, we propose a generic model to evaluate the relationship of connectivity, memory size, communication overhead and security in fully self-organized WANETs. Based on some reasonable assumptions on node deployment and mobility, we show that when the average number of authenticated neighbors of each node is Theta(1), with respect to the network size n, most of the nodes can be securely connected, forming a connected secure backbone, i.e., the secure network percolates. This connected secure backbone can be utilized to break routing-security dependency loop, and provide enough derived secure links connecting isolated nodes with the secure backbone in a multi-hop fashion, which leads to the secure connectivity of the whole network.