Hierarchical data security in a Query-By-Example interface for a shared database

Whenever a shared database resource, containing critical patient data, is created, protecting the contents of the database is a high priority goal. This goal can be achieved by developing a Query-By-Example (QBE) interface, designed to access a shared database, and embedding within the QBE a hierarchical security module that limits access to the data. The security module ensures that researchers working in one clinic do not get access to data from another clinic. The security can be based on a flexible taxonomy structure that allows ordinary users to access data from individual clinics and super users to access data from all clinics. All researchers submit queries through the same interface and the security module processes the taxonomy and user identifiers to limit access. Using this system, two different users with different access rights can submit the same query and get different results thus reducing the need to create different interfaces for different clinics and access rights.