Markus Lorch Seth Proctor Rebekah Lepro Dennis G. Kafura Sumit Shah First experiences using XACML for access control in distributed systems. 25-37 2003 conf/xmlsec/2003 XML Security http://doi.acm.org/10.1145/968559.968563 db/conf/xmlsec/xmlsec2003.html#LorchPLKS03