The viewing of recorded events after the fact using a closed-circuit TV camera is considered a
正解: B
Detective security controls are like a burglar alarm. They detect and report
an unauthorized or undesired event (or an attempted undesired event). Detective security
controls are invoked after the undesirable event has occurred. Example detective security
controls are log monitoring and review, system audit, file integrity checkers, and motion
detection.
Visual surveillance or recording devices such as closed circuit television are used in
conjunction with guards in order to enhance their surveillance ability and to record events
for future analysis or prosecution.
When events are monitored, it is considered preventative whereas recording of events is
considered detective in nature.
Below you have explanations of other types of security controls from a nice guide produce
by James Purcell (see reference below):
Preventive security controls are put into place to prevent intentional or unintentional
disclosure, alteration, or destruction (D.A.D.) of sensitive information. Some example
preventive controls follow:
Policy - Unauthorized network connections are prohibited.
Firewall - Blocks unauthorized network connections.
Locked wiring closet - Prevents unauthorized equipment from being physically plugged into
a network switch.
Notice in the preceding examples that preventive controls crossed administrative, technical,
and physical categories discussed previously. The same is true for any of the controls
discussed in this section.
Corrective security controls are used to respond to and fix a security incident. Corrective
security controls also limit or reduce further damage from an attack. Examples follow:
Procedure to clean a virus from an infected system
A guard checking and locking a door left unlocked by a careless employee
Updating firewall rules to block an attacking IP address
Note that in many cases the corrective security control is triggered by a detective security
control.
Recovery security controls are those controls that put a system back into production after
an incident. Most Disaster Recovery activities fall into this category. For example, after a
disk failure, data is restored from a backup tape.
Directive security controls are the equivalent of administrative controls. Directive controls direct that some action be taken to protect sensitive organizational information. The directive can be in the form of a policy, procedure, or guideline.
Deterrent security controls are controls that discourage security violations. For instance, "Unauthorized Access Prohibited" signage may deter a trespasser from entering an area. The presence of security cameras might deter an employee from stealing equipment. A policy that states access to servers is monitored could deter unauthorized access.
Compensating security controls are controls that provide an alternative to normal controls that cannot be used for some reason. For instance, a certain server cannot have antivirus software installed because it interferes with a critical application. A compensating control would be to increase monitoring of that server or isolate that server on its own network segment.
Note that there is a third popular taxonomy developed by NIST and described in NIST Special Publication 800-53, "Recommended Security Controls for Federal Information Systems." NIST categorizes security controls into 3 classes and then further categorizes the controls within the classes into 17 families. Within each security control family are dozens of specific controls. The NIST taxonomy is not covered on the CISSP exam but is one the CISSP should be aware of if you are employed within the US federal workforce.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 10: Physical security (page 340). and CISSP Study Guide By Eric Conrad, Seth Misenar, Joshua Feldman, page 50-52 and Security Control Types and Operational Security, James E. Purcell, http://www.giac.org/cissp-papers/207.pdf
