Fault tolerant authentication in mobile computing

Survivability and secure communications are essential in a mobile computing environment. In a secured network, all the hosts in the local network must be authenticated before they communicate with the hosts outside the network. The failure of the nodes/agents that authenticate the hosts may completely detach the hosts from the rest of the network. In this paper, we describe two techniques to eliminate such a single point of failure. Both of these techniques make use of backup servers, but they are architecturally different. We address the scalability issue of the techniques proposed by a cluster-based scheme where the front-end directs the requests to a group of back-end machines.