What is Intrusion Tolerance

We believe that the research and development of intrusion tolerant systems will gain more momentum as more and more services are offered online. The expectation of such services is high, considering their essential roles in everyday operations of businesses and individuals as well. The impact of service unavailability and security breaches will only be more serious. In this chapter, we will survey the state of the art techniques for building intrusion tolerant systems. We will also illustrate a few most urgent open issues for future research. Finally, we point out that to build secure and dependable systems, we need a concerted effort in intrusion prevention, intrusion detection, and intrusion tolerance.