Developing a heterogeneous intrusion tolerant CORBA system

Intrusion tolerant systems provide high-integrity and high-availability services to their clients in the face of successful attacks from an adversary. The Intrusion Tolerant Distributed Object Systems (ITDOS) research project is developing an architecture for a heterogeneous intrusion tolerant distributed object system. ITDOS integrates a Byzantine Fault Tolerant multicast protocol into an open-source CORBA ORB to provide intrusion tolerant middleware. This foundation allows up to f simultaneous Byzantine failures of replicated servers in a system of at least 3f+1 replicas. Voting on unmarshalled CORBA messages allows heterogeneous application implementations for a given service, allowing for greater diversity in implementation and greater survivability. Symmetric encryption session keys generated by distributed pseudo-random function techniques provide confidential client-server communications. This paper overviews the ITDOS architecture, discusses some of the challenging technical issues related to intrusion tolerance in heterogeneous middleware systems, and offers views on future areas of work.