Page 1392 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

or superclass) are inherited by another subclass (child).

Delegation Delegation is the forwarding of a request by an object to
another object or delegate. An object delegates if it does not have a

method to handle the message.

Polymorphism A polymorphism is the characteristic of an object
that allows it to respond with different behaviors to the same message
or method because of changes in external conditions.

Cohesion Cohesion describes the strength of the relationship
between the purposes of the methods within the same class.

Coupling Coupling is the level of interaction between objects. Lower

coupling means less interaction. Lower coupling provides better
software design because objects are more independent. Lower
coupling is easier to troubleshoot and update. Objects that have low
cohesion require lots of assistance from other objects to perform tasks
and have high coupling.

Assurance

To ensure that the security control mechanisms built into a new
application properly implement the security policy throughout the

lifecycle of the system, administrators use assurance procedures.
Assurance procedures are simply formalized processes by which trust
is built into the lifecycle of a system. The Common Criteria provides a
standardized approach to assurance used in government settings.

Avoiding and Mitigating System Failure

No matter how advanced your development team, your systems will
likely fail at some point in time. You should plan for this type of failure
when you put the software and hardware controls in place, ensuring

that the system will respond appropriately. You can employ many
methods to avoid failure, including using input validation and creating
fail-safe or fail-open procedures. Let’s talk about these in more detail.

Input Validation As users interact with software, they often provide
information to the application in the form of input. This may include
typing in values that are later used by a program. Developers often