Hierarchical Key Agreement Protocol for Wireless Sensor Networks

Wireless sensor network promises ubiquitous data collection and processing for variety of commercial, healthcare and military applications. Practical realization of WSN applications is possible only after assuring network security. Cryptographic key distribution is an important phase in network security which establishes initial trust in the network. Security protocol implementation in WSN is limited by resource constrained nature of sensor nodes. The key distribution algorithm satisfying security requirements of given WSN application should be implemented with minimum communication and memory overhead. As a solution to this problem, hierarchical key management technique is proposed in this paper. Symmetric key pre-distribution technique with less computational overhead and ID-based asymmetric key (IBK) distribution technique with less communication overhead are applied simultaneously in the network at different levels. Resilience strength and resource overhead of the proposed scheme is compared with both symmetric and asymmetric techniques.