Implementation of MLS/DBMS Models - Multilevel Security for Relational Databases - page 64

Table 3.1 Comparative Study for Multilevel Database Models

RESTRICTION
OF THE
SCOPE OF AN
UPDATE

PROBLEM
MODEL

PROLIFERATION
PROBLEM

SEMANTIC
AMBIGUITY

DISBELIEF
IN A TUPLE SIMPLICITY

SeaView Not solved Not solved Solved Not solved Very simple

Jajodia-Sandhu Solved Not solved Solved Not solved Simple

Smith-Winslett Solved Solved Not solved Not solved Simple

MLR Solved Solved Solved Not solved Complex

BCMLS Solved Solved Solved Solved Very Complex

3.7 Comparative Study for Multilevel Database Models

Table 3.1 illustrates the strengths and weaknesses of each model of
the multilevel security database models.

3.8 Summary

Many multilevel relational models have been proposed; different
models offer different advantages. In this chapter, we explained the
implementation of DML operations such as SELECT, INSERT,
UPDATE, and DELETE for each model of the multilevel secure
database models. From the implementation procedures we found that
MLR is secure, unambiguous, and powerful because it provides mul-
tilevel relations with element-level labeling as a natural extension of
the traditional relational data model. MLR introduces several new
concepts (notably, data-borrow integrity and the UPLEVEL state-
ment) and significantly redefines existing concepts (polyinstantiation
and referential integrity as well as data manipulation operations).