User interaction design for secure systems

Abstract

The security of any system that is configured or operated by human beings depends on the information conveyed by the user interface, the decisions of the users, and the interpretation of their actions. This paper establishes some starting points for reasoning about security from a user-centred perspective: it proposes to model systems in terms of actors and actions, and introduces the concept of the subjective actorability state. Ten principles for secure interaction design are identified; examples of real-world problems illustrate and justify the principles.