Eliciting Policy Requirements for Critical National Infrastructure Using the IRIS Framework

Despite existing work on dealing with security and usability concerns during the early stages of design, there has been little work on synthesising the contributions of these fields into processes for specifying and designing systems. Without a better understanding of how to deal with both concerns at an early stage, the design process risks disenfranchising stakeholders, and resulting systems may not be situated in their contexts of use. This paper presents the IRIS process framework, which guides technique selection when specifying usable and secure systems. The authors illustrate the framework by describing a case study where the process framework was used to derive missing requirements for an information security policy for a UK water company following reports of the Stuxnet worm. The authors conclude with three lessons informing future efforts to integrate Security, Usability, and Requirements Engineering techniques for secure system design.