How to Design Connected Sensor Networks that Are Provably Secure

We give, for the first time, a precise mathematical analysis of the connectivity and security properties of sensor networks that make use of the random pre-distribution of keys. We also show how to set the parameters– pool and key-ring size– in such a way that the network is not only connected with high probability via secure links, but also provably secure, in the following sense: we formally show that any attacker that captures sensors at random with the aim of compromising a constant fraction of the secure links, must capture at least a constant fraction of the nodes of the network. In the context of wireless sensor networks where random predistribution of keys is employed, we are the first to provide a mathematically precise proof, with a clear indication of parameter choice, that two crucial properties – connectivity via secure links and resilience against malicious attacks– can be obtained simultaneously. Our theoretical results are complemented by extensive simulations that reinforce our main conclusions.