A novel dual-key management protocol based on a merarchical multicast infrastructure in mobile Internet

This paper describes a secure multicast infrastructure for large-scale group communications in Mobile Internet and proposes a key management protocol based on the infrastructure. The multicast communication domain is logically divided into several administrative areas with a key server associated with each area. All the key servers participate in a Public Key Infrastructure (PKI) as trusted entities known by the subgroup members. Therefore, it's efficient to minimize the re-key overhead implemented in the mobile host tier. The simulation results show that the proposed protocol has better performance compared to the centralized protocols without PKI support. The numbers of the real re-key messages and the re-key events are reduced to approximately 30% and 65%, respectively.