  The increasing pace of data collection has led to increasing awareness of
privacy risks, resulting in new data privacy regulations like General data
Protection Regulation (GDPR). Such regulations are an important step, but
automatic compliance checking is challenging. In this work, we present a new
paradigm, Data Capsule, for automatic compliance checking of data privacy
regulations in heterogeneous data processing infrastructures. Our key insight
is to pair up a data subject's data with a policy governing how the data is
processed. Specified in our formal policy language: PrivPolicy, the policy is
created and provided by the data subject alongside the data, and is associated
with the data throughout the life-cycle of data processing (e.g., data
transformation by data processing systems, data aggregation of multiple data
subjects' data). We introduce a solution for static enforcement of privacy
policies based on the concept of residual policies, and present a novel
algorithm based on abstract interpretation for deriving residual policies in
PrivPolicy. Our solution ensures compliance automatically, and is designed for
deployment alongside existing infrastructure. We also design and develop
PrivGuard, a reference data capsule manager that implements all the
functionalities of Data Capsule paradigm.
