Implementation of MLS/DBMS Models - Multilevel Security for Relational Databases - page 55

Figure 3.14 illustrates the flow chart for the Xview (label) procedure
in the belief-consistent model.

3.6.1.2 Pl (Label) Procedure This procedure returns the primary level
of the security label [34]—for example, L = ucs, Pl (L) = u.

• Step 1: get the label as input parameter for the procedure.
• Step 2: break the label into parts.
• Step 3: return the first part that has a belief value equal to true.

Figure 3.15 illustrates the flow chart for the Pl (label) procedure in the
belief-consistent model.

Get the label as input
parameter for the procedure

Break label into parts

Get user class L(user)

Set i = 1

i = i + 1 I ≤ L(user)

Ye s No

Pack new lable with parts
that user can see

Return new label

End

Figure 3.14 Flow chart for Xview (label) procedure in a belief-consistent model.