CIAM Access Control Models 2 — Questions and Answers
Question 1: Which access control model uses security labels and clearance levels to enforce a 'no read up, no write down' policy?
- Role-Based Access Control (RBAC)
- Bell-LaPadula Model (Correct answer)
- Biba Integrity Model
- Discretionary Access Control (DAC)
Correct answer: Bell-LaPadula Model
Bell-LaPadula enforces confidentiality by preventing subjects from reading data at higher classifications (no read up) and writing to lower classifications (no write down).
Question 2: In the Biba Integrity Model, the 'no write up' property means that a subject:
- Cannot write to objects at a higher integrity level (Correct answer)
- Cannot read objects at a lower integrity level
- Cannot execute programs at any integrity level
- Cannot modify its own security label
Correct answer: Cannot write to objects at a higher integrity level
In Biba, subjects cannot write to objects at higher integrity levels to prevent corrupting trusted data with less-trusted data.
Question 3: Which property of the Clark-Wilson model requires that all data modifications be performed by authorized programs called Transformation Procedures (TPs)?
- Simple Security Property
- Certification Rule 1 (C1)
- Enforcement Rule 2 (E2) (Correct answer)
- Need-to-Know Principle
Correct answer: Enforcement Rule 2 (E2)
E2 in Clark-Wilson requires that only certified TPs may manipulate Constrained Data Items (CDIs), ensuring integrity through controlled transformation.
Question 4: An organization needs fine-grained access control based on user department, time of day, and resource sensitivity. Which model best fits this requirement?
- Mandatory Access Control (MAC)
- Discretionary Access Control (DAC)
- Attribute-Based Access Control (ABAC) (Correct answer)
- Role-Based Access Control (RBAC)
Correct answer: Attribute-Based Access Control (ABAC)
ABAC evaluates multiple attributes (user, environment, resource) simultaneously, making it ideal for complex, fine-grained policy requirements.
Question 5: In a DAC system, who ultimately controls access to a resource?
- The system administrator exclusively
- The security policy engine
- The resource owner (Correct answer)
- The mandatory security label
Correct answer: The resource owner
In DAC, the owner of a resource has discretion to grant or revoke access to other users, unlike MAC where the system enforces access centrally.
Question 6: Which access control model is most commonly used in operating systems like Windows NTFS through Access Control Lists (ACLs)?
- Mandatory Access Control (MAC)
- Role-Based Access Control (RBAC)
- Discretionary Access Control (DAC) (Correct answer)
- Rule-Based Access Control
Correct answer: Discretionary Access Control (DAC)
NTFS ACLs implement DAC by allowing resource owners and administrators to assign permissions to individual users and groups.
Question 7: The principle that a subject should only access resources necessary for their assigned tasks is called:
- Separation of Duties
- Defense in Depth
- Least Privilege (Correct answer)
- Job Rotation
Correct answer: Least Privilege
Least Privilege restricts subjects to only the minimum access rights required to perform their job functions, reducing the attack surface.
CIAM Access Control Models 2
Which access control model uses security labels and clearance levels to enforce a 'no read up, no write down' policy?