A distributed approach to security in sensornets

Secure communication is an important aspect of any network and it has largely remained unexplored in wireless sensor networks (WSN). Security becomes a major challenge because of ad-hoc and resource constrained nature of sensor networks. In this paper we present a scalable and distributed security protocol, DSPS, for WSN that fits in between the network and the transport layers. DSPS satisfies the essential requirements of secure communication such as data confidentiality, data authentication, data integrity and data freshness. Basic building blocks of our security protocol are key generation-distribution and signatures. The key is a 56-bit random number generated initially by a key server, which is then securely distributed to all the nodes in the cluster. This key is used for encryption. DSPS also supports security critical transactions by dynamically generating a key, which can be shared between two nodes. The simplicity of DSPS allows compatibility with most of the routing protocols.