One of the important challenges in ad hoc mobile networking is providing secure communication among participants. This paper proposes a protocol based on node identities (ID) to establish such a secure environment. The advantage of this protocol is reduced overhead for key computations, compared to the mechanism proposed in 2004 by Varadharajan et al. [1]. Varadharajan’s mechanism uses a public key infrastructure (PKI) cryptosystem, which is an asymmetric cryptosystem; thus, the computational cost is high. In a mobile environment, this can represent significant power consumption.

Lee and Chang propose an authentication system using symmetric key computation, which is much faster than the PKI system. The key computation and distribution overhead can be reduced by 21 percent in the authentication phase and 25 percent in the communication phase. The ID-based mechanism achieves these savings by using a trusted authority to distribute the secret information (public key) to each involved node, avoiding one round of negotiations between the cluster head and the mobile node.

While the ID-based mechanism reduces the computation overhead in authentication and communication, it assumes the existence of a trusted authority for generating and issuing the secret information for all parties involved--cluster heads and mobile nodes. The validity of this assumption and its impact in practice were not carefully examined in the paper. Nevertheless, the computational savings are significant and the ID-based mechanism can have an impact on ad hoc mobile networking.