Providing distributed certificate authority service in cluster-based mobile ad hoc networks

Nodes in a mobile ad hoc network (MANET) are more vulnerable and there is no predefined infrastructure in such a network. Providing secure communication in these networks is an important and challenging problem. Among all proposed schemes, the model of using distributed certificate authorities (CA) based on threshold cryptography and proactive share update using a cluster-based architecture seems to be a promising approach. However, there are two issues that are not well studied in the current literature for this model: (1) how to locate enough CA servers, and (2) how to perform the proactive share update. In this paper, we propose two efficient schemes with low system overhead to tackle these two problems. Compared with existing approaches, our CA architecture provides faster CA services to user nodes at reduced system overhead. The effectiveness of our proposed schemes has been verified by extensive simulation.