Page 690 - (ISC)² CISSP Certified Information Systems Security Professional Official Study Guide

signal, the alarm triggers automatically. Both measures are designed
to prevent intruders from circumventing the detection and alarm

system.

Access Abuses

No matter what form of physical access control is used, a security
guard or other monitoring system must be deployed to prevent abuse,
masquerading, and piggybacking. Examples of abuses of physical
access controls are propping open secured doors and bypassing locks
or access controls. Masquerading is using someone else’s security ID

to gain entry into a facility. Piggybacking is following someone
through a secured gate or doorway without being identified or
authorized personally. Detecting abuses like these can be done by
creating audit trails and retaining access logs.

Audit trails and access logs are useful tools even for physical access
control. They may need to be created manually by security guards. Or
they can be generated automatically if sufficient automated access

control mechanisms (such as smartcards and certain proximity
readers) are in use. The time at which a subject requests entry, the
result of the authentication process, and the length of time the secured
gate remains open are important elements to include in audit trails
and access logs. In addition to using the electronic or paper trail,
consider monitoring entry points with closed circuit television (CCTV)
or security cameras. CCTV enables you to compare the audit trails and

access logs with a visual recording of the events. Such information is
critical to reconstruct the events for an intrusion, breach, or attack.

Emanation Security

Many electrical devices emanate electrical signals or radiation that can
be intercepted by unauthorized individuals. These signals may contain
confidential, sensitive, or private data. Obvious examples of
emanation devices are wireless networking equipment and mobile
phones, but many other devices are vulnerable to interception. Other

examples include monitors, modems, and internal or external media
drives (hard drives, USB thumb drives, CDs, and so on). With the right
equipment, unauthorized users can intercept electromagnetic or radio