Physical security


Physical security describes security
measures that are designed to deny unauthorized access to facilities,
equipment and resources, and to protect personnel and property from damage or
harm. Physical security involves the use of multiple layers of interdependent
systems which include CCTV surveillance, security guards, protective barriers,
locks, access control protocols, and many other techniques.
Overview Physical security systems for protected
facilities are generally intended to: deter potential intruders;
detect intrusions and monitor/record intruders; and
trigger appropriate incident responses. It is up to security designers,
architects and analysts to balance security controls against risks, taking
into account the costs of specifying, developing, testing, implementing,
using, managing, monitoring and maintaining the controls, along with
broader issues such as aesthetics, human rights, health and safety, and societal
norms or conventions. Physical access security measures that are appropriate
for a high security prison or a military site may be inappropriate in an office,
a home or a vehicle, although the principles are similar.
Elements and design =Deterrence methods=
The goal of deterrence methods is to convince potential attackers that a
successful attack is unlikely due to strong defenses.
The initial layer of security for a campus, building, office, or other
physical space uses crime prevention through environmental design to deter
threats. Some of the most common examples are also the most basic:
warning signs or window stickers, fences, vehicle barriers, vehicle
height-restrictors, restricted access points, security lighting and trenches.
Physical barriers Physical barriers such as fences, walls,
and vehicle barriers act as the outermost layer of security. They serve
to prevent, or at least delay, attacks, and also act as a psychological
deterrent by defining the perimeter of the facility and making intrusions seem
more difficult. Tall fencing, topped with barbed wire, razor wire or metal
spikes are often emplaced on the perimeter of a property, generally with
some type of signage that warns people not to attempt to enter. However, in
some facilities imposing perimeter walls/fencing will not be possible or it
may be aesthetically unacceptable; in this case, the outer security perimeter
will be defined as the wallsdoors of the structure itself.
Natural surveillance Another major form of deterrence that
can be incorporated into the design of facilities is natural surveillance,
whereby architects seek to build spaces that are more open and visible to
security personnel and authorized users, so that intruders/attackers are unable
to perform unauthorized activity without being seen. An example would be
decreasing the amount of dense, tall vegetation in the landscaping so that
attackers cannot conceal themselves within it, or placing critical resources
in areas where intruders would have to cross over a wide, open space to reach
them. Security lighting
Security lighting is another effective form of deterrence. Intruders are less
likely to enter well-lit areas for fear of being seen. Doors, gates, and other
entrances, in particular, should be well lit to allow close observation of people
entering and exiting. When lighting the grounds of a facility,
widely-distributed low-intensity lighting is generally superior to small
patches of high-intensity lighting, because the latter can have a tendency
to create blind spots for security personnel and CCTV cameras. It is
important to place lighting in a manner that makes it difficult to tamper with,
and to ensure that there is a backup power supply so that security lights
will not go out if the electricity is cut off.
=Intrusion detection and electronic surveillance=
Alarm systems and sensors Alarm systems can be installed to alert
security personnel when unauthorized access is attempted. Alarm systems work
in tandem with physical barriers, mechanical systems, and security guards,
serving to trigger a response when these other forms of security have been
breached. They consist of sensors including motion sensors, contact
sensors, and glass break detectors. However, alarms are only useful if there
is a prompt response when they are triggered. In the reconnaissance phase
prior to an actual attack, some intruders will test the response time of
security personnel to a deliberately tripped alarm system. By measuring the
length of time it takes for a security team to arrive, the attacker can
determine if an attack could succeed before authorities arrive to neutralize
the threat. Loud audible alarms can also act as a psychological deterrent, by
notifying intruders that their presence has been detected. In some
jurisdictions, law enforcement will not respond to alarms from intrusion
detection systems unless the activation has been verified by an eyewitness or
video. Policies like this one have been created to combat the 94–99 percent rate
of false alarm activation in the United States.
Video surveillance Surveillance cameras can be a deterrent
when placed in highly visible locations, and are also useful for incident
verification and historical analysis. For example, if alarms are being
generated and there is a camera in place, the camera could be viewed to
verify the alarms. In instances when an attack has already occurred and a camera
is in place at the point of attack, the recorded video can be reviewed. Although
the term closed-circuit television is common, it is quickly becoming outdated
as more video systems lose the closed circuit for signal transmission and are
instead transmitting on IP camera networks.
Video monitoring does not necessarily guarantee that a human response is made
to an intrusion. A human must be monitoring the situation in real time in
order to respond in a timely manner. Otherwise, video monitoring is simply a
means to gather evidence to be analyzed at a later time. However, advances in
information technology are reducing the amount of work required for video
monitoring, through automated video analytics.
=Access control=Access control methods are used to
monitor and control traffic through specific access points and areas of the
secure facility. This is done using a variety of systems including CCTV
surveillance, identification cards, security guards, and
electronic/mechanical control systems such as locks, doors, turnstiles and
gates. Mechanical access control systems
Mechanical access control systems include turnstiles, gates, doors, and
locks. Key control of the locks becomes a problem with large user populations
and any user turnover. Keys quickly become unmanageable, often forcing the
adoption of electronic access control. Electronic access control systems
Electronic access control manages large user populations, controlling for user
lifecycles times, dates, and individual access points. For example a user’s
access rights could allow access from 0700h to 1900h Monday through Friday and
expires in 90 days. These access control systems are often interfaced with
turnstiles for Entry control in buildings to prevent unauthorized
access. The use of turnstiles also reduces the need for additional security
personnel to monitor each individual entering the building allowing faster
throughput. An additional sub-layer of
mechanical/electronic access control protection is reached by integrating a
key management system to manage the possession and usage of mechanical keys
to locks or property within a building or campus.
Identification systems and access policies
Another form of access control includes the use of policies, processes and
procedures to manage the ingress into the restricted area. An example of this
is the deployment of security personnel conducting checks for authorized entry
at predetermined points of entry. This form of access control is usually
supplemented by the earlier forms of access control, or simple devices such
as physical passes.=Security personnel=
Security personnel play a central role in all layers of security. All of the
technological systems that are employed to enhance physical security are useless
without a security force that is trained in their use and maintenance, and which
knows how to properly respond to breaches in security. Security personnel
perform many functions: as patrols and at checkpoints, to administer electronic
access control, to respond to alarms, and to monitor and analyze video.
See also Alarm management
Biometrics Biometric device
Boundaries of Security Report Burglar alarm
Computer security Door security
Executive protection Guard tour patrol system
Information security Logical security
Physical Security Professional School security
Security engineering Surveillance
References

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