1. An access control system providing access control to at least one information resource associated with at least one application within a computer network, the access control system comprising: a plurality of context sources being relevant to the at least one application and providing context information; a constraint specification console providing an interface to specify application specific constraints based on the context sources; a rule engine capable of handling facts and applying inference rules on those facts, the rule engine storing the rules; an application specific constraint enforcement point configured to receive access requests, hence querying facts and further being responsible to make access decisions regarding the information resource based on those facts and on application specific constraints; and a rule engine adaptor acting as connecting component to interconnect the rule engine with the context sources, the constraint specification console and the enforcement point, respectively, and as intermediary in communication of the rule engine with the context sources, the constraint specification console and the enforcement point, respectively, so as to allow access control to the at least one information resource based on specified application specific constraints with regard to context information originating from the context sources, context information being provided by a context source being expressed as the facts within the rule engine.
1. An access control system providing access control to at least one information resource associated with at least one application within a computer network, the access control system comprising: a plurality of context sources being relevant to the at least one application and providing context information; a constraint specification console providing an interface to specify application specific constraints based on the context sources; a rule engine capable of handling facts and applying inference rules on those facts, the rule engine storing the rules; an application specific constraint enforcement point configured to receive access requests, hence querying facts and further being responsible to make access decisions regarding the information resource based on those facts and on application specific constraints; and a rule engine adaptor acting as connecting component to interconnect the rule engine with the context sources, the constraint specification console and the enforcement point, respectively, and as intermediary in communication of the rule engine with the context sources, the constraint specification console and the enforcement point, respectively, so as to allow access control to the at least one information resource based on specified application specific constraints with regard to context information originating from the context sources, context information being provided by a context source being expressed as the facts within the rule engine. 4. An access control system according to claim 1 , wherein the rule engine adaptor is configured to translate queries about facts queried by the constraint enforcement point into a representation that is interpretable by the rule engine and answers to such translated queries provided by the rule engine into a representation that is interpretable by the constraint enforcement point accordingly.