Object Normal Form, Fourth Normal Form and Their Application to Database Security

Abstract

An important question in database schema design concerns the effort required to maintain data consistency under updates. Similarly, an important question in database security concerns the effort required to maintain data confidentiality under inference attacks. Previous work has addressed these questions for the popular class of functional dependencies. In this paper, we will extend solutions to the more expressive class of multivalued dependencies. In particular, we will show that schemata in Fourth Normal Form with a unique minimal key require very little effort to maintain data consistency, and can guarantee confidentiality under inference attacks by access control only.