Design Diversity and the Immune System Paradigm: Cornerstones for Information System Survivability

The Call for Participation of ISW-2000 defines information survivability as “the ability of a system to continue to fulfill its mission in the presence of attacks, accidents, or failures”. This position paper presents two concepts: the design diversity technique [1, 2] and the immune system paradigm [3] that already have been found to be useful in assuring the dependability of mission-critical information systems. The above concepts as well as the concept of fault tolerance [3, 4] have originated in the research that the author and his associates have conducted since 1960 [5]. The research has shown that these concepts have the potential to enhance information survivability in the presence of attacks as well [6–9]. Our goal at ISW-2000 is to bring the potential usefulness of the concepts to the attention of the survivability community. Fault tolerance, design diversity and the immune system paradigm become especially important for information survivability when mission-critical systems are built using COTS hardware and software components. Most COTS components have very few, if any at all, built-in features that support survivability, therefore the defenses have to be introduced at the system design level. The remainder of this position paper summarizes: (1) the threats to information survivability; (2) the defenses, i.e., the technique of design diversity and the use of the immune system paradigm; and (3) the first example of their joint application: the recently described “fault tolerance infrastructure for dependable computing with COTS components” [10].