Efficient Node Admission and Certificateless Secure Communication in Short-Lived MANETs

Decentralized node admission is an essential and fundamental security service in mobile ad hoc networks (MANETs). It is needed to securely cope with dynamic membership and topology as well as to bootstrap other important security primitives (such as key management) and services (such as secure routing) without the assistance of any centralized trusted authority. An ideal admission technique must involve minimal interaction among MANET nodes, since connectivity can be unstable. Also, since MANETs are often composed of weak or resource-limited devices, admission must be efficient in terms of computation and communication. Most previously proposed admission protocols are prohibitively expensive and require heavy interaction among MANET nodes. In this paper, we focus on a common type of MANET that is formed on a temporary basis, and present a secure, efficient, and a fully noninteractive admission technique geared for this type of a network. Our admission protocol is based on secret sharing techniques using bivariate polynomials. We also present a new scheme that allows any pair of MANET nodes to efficiently establish an on-the-fly secure communication channel.