Estimation of communication overhead during Pair-wise key establishment in wireless sensor networks

Node join authentication and pair-wise key establishment are essential services to provide confidentiality and authentication to the data communication between any two nodes in a network. Since wireless sensor networks are equipped with resource constrained nodes and therefore energy efficient protocol design is required to provide long network life, we have made an analysis of communication overhead for executing the essentially required security protocols for these networks. Distributed schemes always claim to be with better features than centralized schemes. Therefore, we have chosen security protocols, centralized and distributed in nature and estimated the average number of transmissions required in the network for all nodes to authenticate and establish the essential pair-wise keys. The simulation and analysis results show that the communication overhead of centralized scheme is 65% less compared to the distributed scheme. Also we have observed that because of the special communication pattern in sensor networks, many nodes in the network may be bottlenecks in communication even in distributed schemes, similar to centralized schemes.