Securing a tiered re-taskable sensing system

Sensor Networks are widely used in several application domains thanks to their data acquisition and data processing capabilities. They are well suited to a multitude of monitoring and surveillance applications and are often involved in mission-critical tasks, thus making security a primary concern. Many architectures and protocols have been proposed to address this issue, mainly based on cryptographic operations, but it still represents an open research area: such techniques in fact, to be effective, often require complex computations and a large amount of dedicated resources, which are not available on sensor platforms according to the existing technology. Nevertheless, if considering tiered sensor networks, where tiny motes coexist with more powerful nodes, it is possible to perform some complex and efficient security schemes by exploiting the different capabilities of such nodes. In this paper we present an secure architectural proposal of the Tenet system, a tiered re-taskable sensor network architecture. Specifically, we have integrated some security library into the Tenet architecture in order to implement a hybrid cryptosystem. The latter combines symmetric and asymmetric cryptographic schemes to benefit of the security provided by asymmetric protocols and the better performance of symmetric ones.