The Privacy Option Language : Specification & Implementation

The data protection laws in Europe require that data controllers provide privacy policies to inform individuals about the prospective processing of their personal data. The ever growing expressiveness of privacy policy languages allows to specify policies in a growing number of details. This and new options for policy negotiations transformed rather general privacy policies into specific privacy contracts between the data controller and the individual. In this report, we specify a privacy contract language and call it the Privacy Option Language. It is modelled after the analogy between financial option contracts and data disclosures which has been presented in previous work and led to the Privacy Option notion. The language specification provides privacy by design through its data minimisation provisions, i.e., all contracts are automatically reduced to their canonical form so that individual differences in the contract formulation are inherently normalised. The language specification is extensible in two ways. First, hooks are specified in the core language and can be used to connect sublanguages. The freedom to choose any suitable sublanguage allows to specify language details independent of the core language. Second, the Privacy Option Language itself can be used as a sublanguage within a more general-domain language. We give examples for both types of extensions. Additionally, we provide tools for evaluating semantics such as human-readable presentations of Privacy Options and contract management. The definitions of the semantics are kept simple and serve as templates for more practical ones. All functionality can be checked by interactive tests in a standard multi-purpose programming language interpreter, since the Privacy Option Language is specified as an embedded domain-specific language within Haskell. Hands-on examples are provided along with the language specification.PETweb I