Security and privacy requirements in ubiquitous systems need a sophisticated policy language with features to express access restrictions and obligations.#R##N#  Ubiquitous systems involve multiple actors owning sensitive data concerning aspects such as location, discrete and continuous time, multiple roles that can be shared among actors or evolve over time.#R##N#  Policy consistency is an important problem in  languages supporting these aspects.#R##N#  In this paper we present an abstract language (AAL) to specify most of these security and privacy features and compare it with XACML.#R##N#  We also classified the existing conflict detection mechanisms for XACML in dynamic, testing, or static detection.#R##N#  A thorough analysis of these mechanisms reveals that they have several weaknesses and they are not applicable in our context.#R##N#  We advocate for a classic approach using the notion of logical consistency to detect conflicts in AAL.
['Jean-Claude Royer', 'Anderson Santana de Oliveira']
AAL and Static Conflict Detection in Policy