Referential secrecy

A referential secrecy model is presented that simplifies automatic data classification within a relational database. The model captures the secrecy semantics that reflect the dependencies among foreign key references. These dependencies form the basis for specifying classification constraints, without the complexity of rule-based or view-based mechanisms. The secrecy semantics are expressed within the database schema as parameters to the foreign key definitions. Data classification is a function of the access levels of the foreign key reference tuples, as well as the access class of the subject