Which of the following statements relating to the Bell-LaPadula security model is FALSE (assuming the Strong Star property is not being used) ?

The correct answer is C. A subject is not allowed to read down. Bell-LaPadula is a confidentiality-focused model with two core rules: the Simple Security Property ('No Read Up') - subjects cannot read objects classified above their clearance level - and the Star (*) Property ('No Write Down') - subjects cannot write to objects below their…

Submitted by kim_seoul· Apr 18, 2026Access Controls

Question

Which of the following statements relating to the Bell-LaPadula security model is FALSE (assuming the Strong Star property is not being used) ?

Options

AA subject is not allowed to read up.
BThe property restriction can be escaped by temporarily downgrading a high level subject.
CA subject is not allowed to read down.
DIt is restricted to confidentiality.

How the community answered

(25 responses)

A
8% (2)
C
88% (22)
D
4% (1)

Explanation

Bell-LaPadula is a confidentiality-focused model with two core rules: the Simple Security Property ('No Read Up') - subjects cannot read objects classified above their clearance level - and the Star (*) Property ('No Write Down') - subjects cannot write to objects below their classification level. Reading DOWN (to lower-classified objects) is explicitly ALLOWED, making statement C false. Statement A is true (no read up). Statement B is true - a known weakness is that temporarily downgrading a high-clearance subject bypasses the write-down restriction. Statement D is true - Bell-LaPadula addresses only confidentiality, not integrity.

Topics

#Bell-LaPadula#Security Models#Confidentiality#Mandatory Access Control

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