How can Cloud Users be Supported in Deciding on, Tracking and Controlling How their Data are Used?

Transparency is a basic privacy principle and factor of social trust. However, the processing of personal data along a cloud chain is often rather intransparent to the data subjects concerned. Transparency Enhancing Tools (TETs) can help users in deciding on, tracking and controlling their data in the cloud. However, TETs for enhancing privacy also have to be designed to be both privacy-preserving and usable. In this paper, we provide requirements for usable TETs for the cloud. The requirements presented in this paper were derived in two ways; at a stakeholder workshop and through a legal analysis. Here we discuss design principles for usable privacy policies and give examples of TETs which enable end users to track their personal data. We are developing them using both privacy and usability as design criteria.