An Algebra for Enterprise Privacy Policies Closed Under Composition and Conjunction
Dominik Raub and Rainer Steinwandt
A prerequisite for processing privacy-sensitive data with automatic tools is a fine-grained formalization of privacy policies along with appropriate operators to manipulate such policies. The most promising results for the formalization of privacy policies so far have been achieved with the language EPAL resp. its academic counterpart E-P3P.
As shown at ESORICS 2004, in the existing form E-P3P has fundamental limitations in the expressability of composed policies as desired in projects involving multiple departments or enterprises. We describe a Novel Algebraic Privacy Specification (NAPS) which addresses these problems by offering conjunction, composition and scoping operators, which are defined analogously to those known from E-P3P, but exhibit desirable algebraic properties. Most notably NAPS is, in contrast to E-P3P, closed under all of these operators. Also, we show how existing E-P3P policies fit into the NAPS framework.