A Graphical Approach to Security Risk Analysis

Abstract

"The CORAS language is a graphical modeling language used to support the security analysis process with its customized diagrams. The language has been developed within the research project "SECURIS" (SINTEF ICT/University of Oslo), where it has been applied and evaluated in seven major industrial field trials. Experiences from the field trials show that the CORAS language has contributed to a more actively involvement of the participants, and it has eased the communication within the analysis group. The language has been found easy to understand and suitable for presentation purposes. With time we have become more and more dependent on various kinds of computerized systems. When the complexity of the systems increases, the number of security risks is likely to increase. Security analyses are often considered complicated and time consuming. A well developed security analysis method should support the analysis process by simplifying communication, interaction and understanding between the participants in the analysis. This thesis describes the development of the CORAS language that is particularly suited for security analyses where "structured brainstorming" is part of the process. Important design decisions are based on empirical investigations. The thesis has resulted in the following artifacts: - A modeling guideline that explains how to draw the different kind of diagrams for each step of the analysis. - Rules for translation which enables consistent translation from graphical diagrams to text. - Concept definitions that contributes to a consistent use of security analysis terms. - An evaluation framework to evaluate and compare the quality of security analysis modeling languages.