Page 538 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

Exam Essentials

Know details about each of the access control models. Know
the access control models and their functions. The state machine
model ensures that all instances of subjects accessing objects are

secure. The information flow model is designed to prevent
unauthorized, insecure, or restricted information flow. The
noninterference model prevents the actions of one subject from
affecting the system state or actions of another subject. The Take-
Grant model dictates how rights can be passed from one subject to

another or from a subject to an object. An access control matrix is a
table of subjects and objects that indicates the actions or functions
that each subject can perform on each object. Bell-LaPadula subjects
have a clearance level that allows them to access only those objects
with the corresponding classification levels. This enforces
confidentiality. Biba prevents subjects with lower security levels from
writing to objects at higher security levels. Clark-Wilson is an integrity
model that relies on auditing to ensure that unauthorized subjects

cannot access objects and that authorized users access objects
properly. Biba and Clark-Wilson enforce integrity. Goguen-Meseguer
and Sutherland focus on integrity. Graham-Denning focuses on the
secure creation and deletion of both subjects and objects.

Know the definitions of certification and accreditation.
Certification is the technical evaluation of each part of a computer

system to assess its concordance with security standards.
Accreditation is the process of formal acceptance of a certified
configuration from a designated authority.

Be able to describe open and closed systems. Open systems are
designed using industry standards and are usually easy to integrate
with other open systems. Closed systems are generally proprietary
hardware and/or software. Their specifications are not normally

published, and they are usually harder to integrate with other systems.

Know what confinement, bounds, and isolation are.
Confinement restricts a process to reading from and writing to certain
memory locations. Bounds are the limits of memory a process cannot