@techreport{TR-IC-06-05,
  number = {IC-06-05},
  author = {João Porto de Albuquerque},
  title = {Scalable Model-based Policy Refinement and
           Validation for Network Security Systems},
  month = {March},
  year = {2006}, 
  institution = {Institute of Computing, University of Campinas},
  note = {In English, 58 pages.
    \par\selectlanguage{english}\textbf{Abstract}
       This report builds upon previous work on Model-based
       Management, and particularly on the Diagram of Abstract
       Subsystems (DAS) approach, further elaborating on the
       correctness and performance of the automated policy refinement
       process.  The modelling technique and the automated policy
       refinement process are firstly presented to illustrate the
       practical use of the DAS approach. Subsequently, the graphical
       model is formalised using an algebraic notation, which is thus
       utilised to define validation conditions for a layered model,
       i.e. conditions to which a resulting model must comply if the
       lower-level policy sets have been correctly generated. The
       scalability of the refinement algorithms and the additional
       effort needed to validate model instances are also analysed and
       discussed.
  }
}