1. A computer implemented access control system, the system comprising: a database for storing a serialized version of an XACML permissions hierarchy; a memory for storing an original version of the XACML permissions hierarchy; and an XACML serialization engine configured to convert the XACML permissions hierarchy into the serialized version, wherein the serialized version contains a listing of at least a portion of the predicates possible in the XACML permission hierarchy and the effect on each of the portion of the predicates.