A Logic-Route Key Tree based Group Key Management Scheme for Wireless Sensor Networks

Energy efficiency is one of the most essential design considerations because of sensor node's resource constraints in wireless sensor networks (WSNs). Group communication is an important technique to reduce WSNs communication overhead. As an imperative group key management, the logical key tree-based scheme can reduce the number of rekeying messages to O(log N) by building a tree of key encryption keys (KEKs). Unfortunately, it can incur heavy overhead for key update whenever the group member changes. In this paper, in order to simultaneously resolve the transmission security and scalability in WSN group communications, we propose a cluster-based secure and scalable group key management scheme, called LRKT, based on logic key tree and route key tree structure. The proposed LRKT scheme divides a WSN into clusters and generates a route key tree according to the route topology of the WSN. In LRKT, the key updates are confined in a cluster, so the cost of the key updates is reduced efficiently, especially for the case of massive membership changes. Furthermore, a lazy update strategy is used to reduce the rekeying cost. The security analysis shows that the proposed LRKT scheme is secure. In addition, performance simulation results also demonstrate its efficiency in terms of low storage and flexibility when membership changes massively.