Design of an architecture for multiple security levels in wireless sensor networks

With the increased application of wireless sensor networks (WSNs) in military, commercial, and home environments, securing the data in the network is a critical issue. Several security mechanisms, such as TinySec, have been introduced to address the need for security in WSNs. There are many applications, however, which require more than just protecting the data at a single level. For those applications, it is necessary to provide multilevel security (MLS) that can accommodate the different sensitivity levels of information as well as the different clearance levels of the users. In this paper, we apply the concept of MLS to the field of WSNs by employing the approach of multiple security levels (MSL). We employ cryptography techniques to realize the key aspects of MSL: the separation of different security levels and controlled information flow. Specifically, TinyKeyMan is selected as the key management scheme for this design due to its resilience to node compromise attacks. In addition, we evaluate the two dominant costs of the design: 1) communication overhead between different security levels and 2) the cryptography cost on the lifetime of a mote. The MSL design we propose is simple and incurs low developmental costs, making it well-suited to resource constrained WSNs.