Cryptanalysis of a hybrid authentication protocol for large mobile networks

In this paper we analyse a hybrid authentication protocol due to Chien and Jan, designed for use in large mobile networks. The proposed protocol consists of two sub-protocols, namely the intra-domain authentication protocol and the inter-domain authentication protocol, which are used depending on whether the user and the request service are located in the same domain. We show that both sub-protocols suffer from a number of security vulnerabilities.