Towards a Secure and Borderless Collaboration between Organizations: An Automated Enforcement Mechanism

Algorithm 4

Optimizing policies.

Input: XACML document

Forall attribute categories do

 Forall Policy elements do

  evaluate rulesnumber of current policy;

  If rulesnumber ≥ 2 then //policy with one rule does not need optimization

   For i=1 to rulesnumber do

    parse Target of rule i;

    If Target designates current attribute category then

     CurrentValue:=value(attribute category);

     combinedRules:= rule i;

     For j=i+1 to rulesnumber do

      parse Target of rule j;

      If value(attribute category)= CurrentValue then

       combinedRules:= rule j;

     If length(combinedRules) ≥ 2 then

      If length(combinedRules) = rulesnumber then

       alter Target of current Policy element;

       alter combinedRules Targets;

      Else

       create sibling policy with Target designating CurrentValue for attr category;

       alter combinedRules Targets;

       move combinedRules to the new sibling policy;