What mechanism does a system use to compare the security labels of a subject and an object?
Correct Answer: B
Explanation/Reference:
Explanation:
The reference monitor is an abstract machine that mediates all access subjects have to objects, both to ensure that the subjects have the necessary access rights and to protect the objects from unauthorized access and destructive modification. For a system to achieve a higher level of trust, it must require subjects (programs, users, processes) to be fully authorized prior to accessing an object (file, program, resource). A subject must not be allowed to use a requested resource until the subject has proven it has been granted access privileges to use the requested object. The reference monitor is an access control concept, not an actual physical component, which is why it is normally referred to as the "reference monitor concept" or an "abstract machine."
Incorrect Answers:
A: A Validation Module is not what the system uses to compare the security labels of a subject and an object.
C: A Clearance Check is not what the system uses to compare the security labels of a subject and an object.
D: A Security Module is not what the system uses to compare the security labels of a subject and an object.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 362