DiFiSec: An Adaptable Multi-level Security Framework for Event-Driven Communication in Wireless Sensor Networks

State of the art security research in the field of wireless sensor networks has focused on providing security in a coarse-grained, full-fledged and static fashion. This implies providing confidentiality, data authentication, data integrity and freshness to the entire spectrum of communication between the participating nodes in a network. In this paper however we advocate that as a result of a number of factors relating wireless sensor networks, providing security in similar fashion for the entire communication set isn´t a pragmatic approach and does not precisely reflect the application level security requirements. We therefore propose DiFiSec, a dynamic, fine-grained and adaptable security framework that supports various levels of plug gable security for distinct data communication sets depending on the context, environment and criticality of the data. These plug gable security levels can be enacted at the levels of component wirings and receptacles, hence empowering application users to select only the most appropriate security respecting the resource-constrained nature of WSNs. Furthermore, to support system evolution and changing application requirements DiFiSec offers runtime adaptability. A prototype of this system has been implemented on SunSPOT sensor nodes where we have evaluated our approach in comparison with other network security variations.