A-PPL: An accountability policy language

Cloud Computing raises various security and privacy challenges due to the customers' inherent lack of control over their outsourced data. One approach to encourage customers to take advantage of the cloud is the design of new accountability solutions which improve the degree of transparency with respect to data processing. In this paper, we focus on accountability policies and propose A-PPL, an accountability policy language that represents machine-readable accountability policies. A-PPL extends the PPL language by allowing customers to define additional rules on data retention, data location, logging and notification. The use of A-PPL is illustrated with a use case where medical sensors collect personal data which are then stored and processed in the cloud. We define accountability obligations related to this use case and translate them into A-PPL policies as a proof of concept of our proposal.