Cyber Physical Systems (CPS) seamlessly integrate physical objects with technology, thereby blurring the boundaries between the physical and virtual environments. While this brings many opportunities for progress, it also adds a new layer of complexity to the risk assessment process when attempting to ascertain what privacy risks this might impose on an organisation. In addition, privacy regulations, such as the General Data Protection Regulation (GDPR), mandate assessment of privacy risks, including making Data Protection Impact Assessments (DPIAs) compulsory. We present the DPIA Data Wheel, a holistic privacy risk assessment framework based on Contextual Integrity (CI), that practitioners can use to inform decision making around the privacy risks of CPS. This framework facilitates comprehensive contextual inquiry into privacy risk, that accounts for both the elicitation of privacy risks, and the identification of appropriate mitigation strategies. Further, by using this DPIA framework we also provide organisations with a means of assessing privacy from both the perspective of the organisation and the individual, thereby facilitating GDPR compliance. We empirically evaluate this framework in three different real-world settings. In doing so, we demonstrate how CI can be incorporated into the privacy risk decision-making process in a usable, practical manner that will aid decision makers in making informed privacy decisions.

Understanding how to better elicit, specify, and manage requirements for secure and usable software systems is a key challenge in security software engineering, however, there lacks tool-support for specifying and managing the voluminous amounts of data the associated analysis yields. Without these tools, the subjectivity of analysis may increase as design activities progress. This paper describes CAIRIS (Computer Aided Integration of Requirements and Information Security), a step toward tool-support for usable secure requirements engineering. CAIRIS not only manages the elements associated with task, requirements, and risk analysis, it also supports subsequent analysis using novel approaches for analysing and visualising security and usability. The authors illustrate an application of CAIRIS by describing how it was used to support requirements analysis in a critical infrastructure case study.