Information Assurance

13.4. Intrusion Tolerance Through Diverse Replicas

The use of diverse replicas in IRS borrows ideas from the field of natural fault tolerance and from observations of biological systems. By introducing artificial diversity, a common phenomenon in biological systems, an attack specific to a vulnerability in a system cannot affect another system that lacks that vulnerability. Coupled with redundancy, the effect of an attack can be masked, allowing the system to provide continued service in the presence of disruptions. The basic approach is to employ a diverse set of replicas for a given service, such that they provide the same high-level functionality with respect to other services, but their internal designs and implementations differ. The fault-masking ...