  In cluster-based routing protocol (CBRP), two-level hierarchical structure is
successfully used to reduce over-flooding in wireless Ad Hoc networks. As it is
vulnerable to a single point of failure, we propose a new adaptive distributed
threshold scheme to replace the cluster head by a group of cluster heads within
each cluster, called COUNCIL, and distribute the service of single cluster head
to multiple cluster heads using (k,n) threshold secret sharing scheme. An Ad
Hoc network formed by COUNCIL based clusters can work correctly when the number
of compromised cluster heads is smaller than k. To implement this adaptive
threshold scheme in wireless Ad Hoc Networks, membership of the clusters should
be defined in an adaptive way. In this paper, we mainly discuss our algorithm
for forming COUNCIL based clusters using the concept of dominating set from
graph theory.
