Many fault-tolerant group communication middleware systems have been implemented assuming crash failure semantics. While this assumption is not unreasonable, it becomes hard to justify when applications are required to meet high reliability requirements and are built using commercial off the shelf (COTS) components. This paper presents a structured approach to extend a crash-tolerant middleware system into an authenticated Byzantine tolerant one with small modifications to the original system. The proposed approach is based on state machine replication (SMR) and is motivated by the composability features of standard distributed object technologies such as CORBA. SMR is used to assure signal-on-failure (fail-signal) semantics at a level where existing crash-tolerant services can be seamlessly deployed. The resulting system can provide total ordering that has no liveness requirement for termination. We demonstrate the effectiveness of our approach by porting a crash-tolerant CORBA group communication service — the NewTOP system. We also measure the performance of the resulting system.