Key Management for Large Ad Hoc Networks

Security of ad hoc networks faces a big challenge due to unique characteristics of them. Though distributed security schemes are presented for ad hoc scenarios, most of them may not be scalable. This paper proposes a new cluster-based security architecture DCD (Distributed-Centralized-Distributed model) for large ad hoc networks. We focus on intra-cluster key management in large ad hoc environments. The outstanding feature of our scheme is that some cluster members are chosen as DAC (Distributed Authority of a Cluster) and cluster secret is shared among DAC members based on a new secret sharing scheme. It enables flexible and efficient key management while respecting the constraints of ad hoc networks. Share refreshing in clusters can be very easily implemented at periodic intervals.