Full protection specifications in the semantic model for database protection languages

The basic model of semantics for protection languages is reviewed. Advanced protection features are introduced into the model and their impact on authorization and enforcement is discussed. History keeping allows access dependency upon the occurrence of previous data operations. Auxiliary program invocation provides for additional (procedural) protection measures. Extended authorization permits a user to utilize, via authorized procedures, data which are not directly accessible by him. Examples are used to explain each of these features. The enforcement process for full specifications is illustrated with an example.