Self-certified group key generation for ad hoc clusters in wireless sensor networks

Dynamic formation of node clusters is inherently embedded in a wide range of emerging wireless sensor network (WSN) applications. It is expected that security will play a key role in the design and successful deployment of these, as well as many other, applications. The ad-hoc nature and unique power-constraint characteristics of WSN suggest that a prerequisite for achieving security is the ability to encrypt and decrypt confidential data among an arbitrary set of sensor nodes. Consequently, the nodes are required to generate a joint secret key. Elliptic Curve Cryptography (ECC) has emerged as a suitable public key cryptographic foundation for WSN. This paper describes a pragmatic ECC-based methodology for self-certified group key generation in ad hoc clusters of sensor nodes. A novel load-balancing technique and chained data exchange yield reduced overall communications and facilitate an efficient distribution of the computational effort involved.