Explanation/Reference:
Because it is rarely possible or cost effective to eliminate all risks, an attempt is made to reduce risks to an acceptable level through the risk assessment process. This process allows, from a set of potential risks (whether likely or not), to come up with a set of identified, possible risks.
The implementation of security controls allows reducing the identified risks to a smaller set of residual risks. Because these residual risks represent the complete set of situations that could affect system performance, the scope of the contingency plan may be reduced to address only this decreased risk set.
As a result, the contingency plan can be narrowly focused, conserving resources while ensuring an effective system recovery capability.
Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page 7).

Section: Security Operation Adimnistration
Explanation
Explanation/Reference:
Complex Instruction Set Computer (CISC) uses instructions that perform many operations per instruction. It was based on the fact that in earlier technologies, the instruction fetch was the longest part of the cycle.
Therefore, by packing more operations into an instruction, the number of fetches could be reduced. Pipelining involves overlapping the steps of different instructions to increase the performance in a computer. Reduced Instruction Set Computers (RISC) involve simpler instructions that require fewer clock cycles to execute. Scalar processors are processors that execute one instruction at a time.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 5: Security Architectures and Models (page 188).

Section: Access Control
Explanation/Reference:
From the glossary of Computer Security Basics:
The Bell-LaPadula model is the security policy model on which the Orange Book requirements are based.
From the Orange Book definition, "A formal state transition model of computer security policy that describes a set of access control rules. In this formal model, the entities in a computer system are divided into abstract sets of subjects and objects. The notion of secure state is defined and it is proven that each state transition preserves security by moving from secure state to secure state; thus, inductively proving the system is secure.
A system state is defined to be 'secure' if the only permitted access modes of subjects to objects are in accordance with a specific security policy. In order to determine whether or not a specific access mode is allowed, the clearance of a subject is compared to the classification of the object and a determination is made as to whether the subject is authorized for the specific access mode." The Biba Model is an integrity model of computer security policy that describes a set of rules. In this model, a subject may not depend on any object or other subject that is less trusted than itself.
The Clark Wilson Model is an integrity model for computer security policy designed for a commercial environment. It addresses such concepts as nondiscretionary access control, privilege separation, and least privilege. TEMPEST is a government program that prevents the compromising electrical and electromagnetic signals that emanate from computers and related equipment from being intercepted and deciphered.
Source: RUSSEL, Deborah & GANGEMI, G.T. Sr., Computer Security Basics, O'Reilly, 1991.
Also: U.S. Department of Defense, Trusted Computer System Evaluation Criteria (Orange Book), DOD
5200.28-STD. December 1985 (also available here).

The CER is one of the three main performance measurements used in biometrics.

Section: Network and Telecommunications
Explanation/Reference:
The Answer: Call back Systems; Callback systems provide access protection by calling back the number of a previously authorized location, but this control can be compromised by call forwarding.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 35.