Secure Selective Exclusion in Ad Hoc Wireless Network

A wireless sensor network can be seen as a large number (hundreds of thousand) of small (a few cubic millimetres) devices, battery powered, with very limited hardware resources. Such a network has been studied specifically in the ad hoc model, where the sensors autonomously set up a network infrastructure. We propose here an extension to the current wireless ad hoc sensor network (WSN) model (in particular the base station model), by introducing a Supervisor which has very few interactions with the network, it is mobile in itself, it could have more powerful hardware and it is asynchronous with respect to the sensors. Nevertheless, the Supervisor has to interact with the sensor network, for example to invoke the command to exclude from the network a selected sensor. We believe such a model is particularly suitable for, but not limited to, military applications. We then propose a distributed, cooperative, parallel algorithm for this model that assures the following properties: it enforces both the secure exclusion of a selected compromised sensor from the network and the rekeying of the remaining sensors. It has an overall low overhead both in terms of computation and required transmitted messages. It is scalable, since the algorithm requires only limited, local knowledge of the network topology. Finally, it can be adopted, as an independent layer, to enforce secure exclusion in other models.