A security apparatus and method that provides Multi-Level and
Multi-Category Mandatory Access Control (MAC) for controlling access to
data within a database at the granularity of the data record. The access
control mechanism is implemented so that it has no impact on the
database. A standard labeling technology is used in which access to data
is dependent on the label of the accessing entity and the label of the
data being accessed. The data labels designate security access
requirements for data within the database and are stored or generated in
a label server that intercepts access requests to the database from
remote users. User labels define user access rights and are retrieved or
generated and linked to all access requests. The label server compares
the user labels linked to an access request with the data label for the
data requested to determine if user access is granted or denied.