Secure and reliable connectivity in heterogeneous wireless sensor networks

We consider a wireless sensor network secured by a heterogeneous random key predistribution scheme and investigate its reliability against both link and node failures. The heterogeneous random key predistribution scheme is a lightweight security mechanism proposed to secure sensor networks that include nodes with varying levels of resources, features, or connectivity requirements; e.g., regular nodes vs. cluster heads. To capture the reliability of the network against both link and node failures, we consider the case when each link fails independently with probability 1 - α and present conditions (in the form of zero-one laws) on how to scale the parameters of the resulting network so that it is k-connected with high probability, i.e., the network remains connected even if any k - 1 nodes fail or leave the network. Collectively, we obtain a network that is reliable against the probabilistic failure of each link and against the failure of any k - 1 nodes. We present numerical results to support these conditions in the finite-node regime.