Implementing SEID as a Solution for Connecting NKCS

There has been an abundance of research within the last couple of decades in the area of multilevel secure (MLS) databases. Recent work in this field deals with the processing of multilevel transactions, expanding the logic of MLS query languages, and utilizing MLS principles within the realm of E-Business. However, there is a basic flaw within the MLS logic, which obstructs the handling of clearance-invariant aggregate queries and physical-entity related queries where some of the information in the database may be gleaned from the outside world. This flaw stands in the way of a more pervasive adoption of MLS models by the developers of practical applications. This paper clearly identifies for the first time the cause of this impediment – the cover story dependence on the value of a user-defined key. In addition to identifying the problem, the paper proposes a practical solution and illustrates how such a solution improves the applicability and robustness of MLS databases. The paper also describes the changes in the model properties and relational algebra brought by the proposed innovation.