While Privacy by Design (PbD) is prescribed by modern privacy regulations such as the EU’s GDPR, achieving PbD in real software systems is a notoriously difficult task. One emerging technique to realize PbD is Runtime enforcement (RE), in which an enforcer, loaded with a specification of a system’s privacy requirements, observes the actions performed by the system and instructs it to perform actions that will ensure compliance with these requirements at all times.

To be able to use RE techniques for PbD, privacy regulations first need to be translated into an enforceable specification. In this paper, we report on our ongoing work in formalizing the GDPR. We first present a set of requirements and an iterative methodology for creating enforceable formal specifications of legal provisions. Then, we report on a preliminary case study in which we used our methodology to derive an enforceable specification of part of the GDPR. Our case study suggests that our methodology can be effectively used to develop accurate enforceable specifications.