Chapter 4
Layers of Security
Keywords: risk assessment, security technology, vulnerabilities, security
plan, operational security, security clearance, need to know, physical secu-
rity, policies and procedures, proprietary knowledge, surveillance, security
strategies, acceptance, avoidance, diversication, transference, consolidation
Learning Objectives
Aer reading this chapter you should be able to
Understand the security thought process
Understand physical security terminology
Employ a variety of strategies to enhance organizational security
Understand the relationship between security and normal operations
Security Elements
In Chapter1 the groundwork was laid to explore the application of secu-
rity to transportation infrastructure and assets. As noted, security is oen
closely aligned with safety and emergency management within organiza-
tions, each of which has a slightly dierent approach to the challenge of pro-
viding a functional environment. Clear communication among the partners
Introduction to Transportation Security94
may be hindered because each discipline has its own understanding of the
application of security principles. Risk, threat, and vulnerability are also
related concepts that are part of the security evaluation process, but each
discipline may see the challenge through a dierent lens.
Risk Assessment
e rst step in creating a security program is the development of a risk
assessment. Currently, most risk assessment is undertaken from the per-
spective of the security analyst. Hazards to the facility or community—nat-
ural, technological, and human caused—are identied, and an estimate is
made of the damage that might result from each event. e security plan
then considers the application of technology or engineering to maintain
security when faced with such an event. e security expert tends to focus
rst on plans for defense of the facility, and then he or she evaluates the
ecacy of such plans, asking how an adversary could overcome these pro-
tective measures.
Security Technologies
Most security technologies are centuries old in concept, meaning that they
are well understood by adversaries. Modern locks, for example, are just
more sophisticated versions of historical lock and key systems (Figure4.1).
Walls, fences, barbed wire, electried barriers, and electronic detection
systems evolved from protective ramparts. ese well understood systems
give the defenders little advantage over the attackers. More sophisticated
systems like cameras (Figure4.2) and biologically based identiers are just
FIGURE 4.1 Antique locks.
Layers of Security 95
extensions of walls and locks. e plans for many systems are available
from the manufacturer or on the Internet. YouTube has videos teaching key
bumping and lock picking, and hackers successfully interdict even military
computer security systems.
Technology itself is neutral. Its benecial or destructive nature is deter-
mined by who is using it and when it is being used. A slim jim used by a tow
truck driver in a parking lot at 2:00 p.m. is a tool to rescue a child trapped
in an accidentally locked car. A slim jim in the hands of a 15-year- old in a
parking lot at 2:00 a.m. is a burglar’s tool.
e main security value inherent in these technologies is costing the per-
petrator time, which in turn may allow the defenders to respond eectively
and to summon additional assistance, such as from law enforcement, before
a successful security breach. Locks are designed to slow down the entrance
of unauthorized personnel by forcing them to stop and pick the lock. Walls
require time for climbing. Cameras can cost time by forcing the adversar-
ies into a longer path to their objective or stopping their forward motion to
disable the cameras. In fact, if the adversaries are disguised or do not care
that they are identied, the cameras may only be a deterrent in that they
speed the protective response. If the perpetrator knows how many guards
are on- site, the opposition force may simply overpower the defenders as they
respond to the cameras notication of an attack.
Thinking Like a Perpetrator
One of the most eective ways to understand the nuances of security is
to consider the vulnerabilities from the perspective of a criminal/ terrorist
seeking access to the facility, its personnel, and its secure contents and
FIGURE 4.2 Surveillance camera.

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