A System of Privacy Patterns for Informing Users: Creating a Pattern System

The General Data Protection Regulation mandates data protection in the European Union. This includes data protection by design and having privacy-preserving defaults. This legislation has been in force since May 2018, promising severe consequences for violation. Fulfilling its mandate for data protection is not trivial, though. One approach for realizing this is the use of privacy design patterns. We have recently started consolidating such patterns into useful collections. In this paper we improve a subset of these, constructing a pattern system. This helps to identify contextually appropriate patterns. It better illustrates their application and relation to each other. The pattern system guides software developers, so that they can help users understand how their information system uses personal data. To achieve this, we rewrite our patterns to meet specific requirements. In particular, we add implementability and interconnection, while improving consistency and organization. This results in a system of patterns for informing users.