Page 1129 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

difficult for individuals to engage in malicious, fraudulent, or
unauthorized activities and broadens the scope of detection and

reporting. In contrast, individuals may be more tempted to perform
unauthorized acts if they think they can get away with them. With two
or more people involved, the risk of detection increases and acts as an
effective deterrent.

Here’s a simple example. Movie theaters use separation of duties to
prevent fraud. One person sells tickets. Another person collects the

tickets and doesn’t allow entry to anyone who doesn’t have a ticket. If
the same person collects the money and grants entry, this person can
allow people in without a ticket or pocket the collected money without
issuing a ticket. Of course, it is possible for the ticket seller and the
ticket collector to get together and concoct a plan to steal from the
movie theater. This is collusion because it is an agreement between
two or more persons to perform some unauthorized activity. However,
collusion takes more effort and increases the risk to each of them.

Separation of duties policies help reduce fraud by requiring collusion
between two or more people to perform the unauthorized activity.

Similarly, organizations often break down processes into multiple
tasks or duties and assign these duties to different individuals to
prevent fraud. For example, one person approves payment for a valid
invoice, but someone else makes the payment. If one person controlled

the entire process of approval and payment, it would be easy to
approve bogus invoices and defraud the company.

Another way separation of duties is enforced is by dividing the security
or administrative capabilities and functions among multiple trusted
individuals. When the organization divides administration and
security responsibilities among several users, no single person has
sufficient access to circumvent or disable security mechanisms.

Separation of Privilege

Separation of privilege is similar in concept to separation of duties
and responsibilities. It builds on the principle of least privilege and
applies it to applications and processes. A separation-of-privilege
policy requires the use of granular rights and permissions.