Process Algebra and Non-Interference

The information security community has long debated the exact definition of the term `security'. Even if we focus on the more modest notion of confidentiality the precise definitionremains controversial. In their seminal paper [4], Goguen and Meseguer took an important step towards a formalisation of the notion of absence of information flow with the concept of non- interference. This too was found to have problems and limitations, particularly when applied to systems displaying non-determinism which led to a proliferation of refinements of this notion and there is still no consensus as to which of these is `correct'. We show that this central concept in information security is closely related to a central concept of computer science: that of the equivalence of systems. The notion of noninterference depends ultimately on our notion of process equivalence. However what constitutes the equivalence of two processes is itself a deep and controversial question in computer science...

• Type: Conference
• Year: 1999
• Where: CSFW
• Authors: Peter Y. A. Ryan, Steve A. Schneider
• Keywords: Central Concept, CSFW 1999, Information Security, Modest Notion, Security Privacy