Research On Total Order Multicast Protocol In Intrusion Tolerant Group Communication System

Replication is very useful and important to support the realization of intrusion tolerance, including active replication and passive replication. Indeed, group communication is indispensable to both replication technologies. With the throughout analysis on the properties, operation modes and requirements for intrusion tolerance, group communication and replication, an architecture of intrusion-tolerant group communication system is presented in this paper with the emphasizes on its internal structure. Focus on the concept of "Group" and its characteristics, a classification of existing total order multicast protocols is proposed. By far, existing total order multicast protocols are all based on single group or multiple non-overlapped groups assumption, which is not enough to cover all environments. Aimed to implement total order multicast properly in the overlapped groups, a novel total order multicast protocol is presented. Furthermore, considering its efficiency and scalability, we design an alternative total order multicast protocol for overlapped groups by using propagation tree.