Babel: Using a Common Bridge Node to Deliver Multiple Keys in Wireless Sensor Networks

In Wireless Sensor Networks (WSNs), symmetric key schemes may be used to provide security. Recently, a class of random key pre-distribution techniques have been proposed and investigated. Such techniques only guarantee to establish keys for some pairs of physically connected sensors. In this work, we address the issue of delivering secret link keys to each of the source's neighbors in wireless sensor networks. We propose a scheme called Babel that finds a common bridge node to deliver one key to each of the to-be-connected neighbors. The novelty of our scheme is to deliver multiple keys through a common bridge node and regular paths instead of multi-hop secure paths. Since the delivered keys are only disclosed to one node, the common bridge node, key compromise probability of the Babel scheme is significantly lower compared to other delivery techniques.