An Efficient Cluster-Based Proactive Secret Share Update Scheme for Mobile Ad Hoc Networks

When implementing public key security services in mobile ad hoc networks (MANETs), multiple certificate authority (CA) servers are usually adopted to increase the security of the system, with each CA node holding only one share of the private key. To prevent an adversary from collecting a large enough number of shares over a long period of time to compromise the system, the shares will be periodically updated. However, it is not trivial how this update procedure can be done efficiently in a MANET. In this paper, we devise an efficient distributed secret key share update scheme for MANETs based on the cluster architecture. In our scheme, the secret shares are updated first by a small group of server nodes. With the assistance of the cluster head in each cluster, the updated servers then refresh the shares in the remaining servers. We evaluate our scheme by simulation and show that our scheme can expedite the share update process.