The VMS scheme discussed in the preceding problem is often referred to as a ring protectio...

The VMS scheme discussed in the preceding problem is often referred to as a ring protection structure, as illustrated in Figure 3.18. Indeed, the simple kernel/user scheme, as described in Section 3.3, is a two-ring structure. A potential disadvantage of this protection structure is that it cannot readily be used to enforce a “need-to-know” principle. [SILB04] gives this example: If an object is accessible in domain Dj but not in domain Di, then j

Explain clearly what the problem is that is referred to in the preceding paragraph.

Figure 3.18 VAX/VMS Access Modes