Binomial Tree based Key Establishment Schemes for Heterogeneous Wireless Sensor Networks

Abstract

Clustering is one of the techniques used in Wireless Sensor Networks (WSNs) to enhance the network lifetime. Network lifetime can further be improved by reducing the number of computations performed by cluster members and cluster head. This paper presents two low cost key establishment schemes for clustered sensor networks which use binomial trees for managing the clusters: BLKH (Binomial tree based Logical Key Hierarchy) scheme and BWLKH (Binomial tree based Wireless Logical Key Hierarchy) scheme. The proposed schemes avoid rebalancing of key trees during join/leave operations by replacing logical key tree by binomial key tree. In both schemes, the number of new keys generated and the number of encryptions performed during node addition/eviction are less compared to LKH++ and WLKH schemes and are quite efficient. The proposed schemes increase the performance of a sensor node by minimizing the computations at cluster members. Thus, the schemes are scalable and suitable for large scale sensor networks.