Introducing Physical Security 407
Voice Recognition This system determines who you are by using voice analysis.
Keyboard Dynamics This biometric method analyzes the user’s speed and pattern of
typing.
No matter what means of authentication you use as a physical access control, it needs
to fit the situation in which it will be applied. For example, if the processing time of a
biometric system is slow, users will tend to just hold the door open for others rather than
wait for the additional processing time. Another example is iris scanners, which may be
installed at all employee entrances, yet later cause complaints from employees who are
physically challenged or in wheelchairs since they cannot easily use the newly installed
system. Consider who will be using the system and if it may be appropriate given the
situation and user base.
Walls, Ceilings, and Floors
Of course surrounding any facility and rooms are the walls, ceilings, and floors, which
you should always consider when doing a physical penetration or assessment. Walls can
be constructed and designed many different ways, but each situation should be considered
carefully and assessed by someone who knows the various details that must be taken
into account.
First, look at the construction and composition of walls. Walls protecting key rooms
within a facility should be sturdy and provide an effective barrier as well as a strong point
for anchoring doors.
One often overlooked point is whether the walls are constructed as so-called “false”
walls or if they are actually fully constructed. In some facilities, the walls may not extend
up beyond the ceiling, which may not seem like a problem normally. However, in some
cases facilities employ what is known as a false ceiling, which is a wall that only goes up to
a drop ceiling and does not extend past the drop ceiling to the roof of the building. In cases
like this, it is possible for an intruder to gain access to a restricted area simply by entering a
crawlspace and going over the wall.
In addition, any ceiling-mounted air ducts should be small enough to prevent an intruder
from crawling through them.
One other area to consider is that area under your feet, the floor. In some buildings the
floor is actually raised, meaning there exists a space underneath it. This space can present
problems up to and including the passage of intruders or the placement of listening devices
or other equipment.
Finally, something that may not seem as obvious is how to protect facilities against
vehicles. For example, how can a car or truck be stopped from backing into a window
breaking it and allowing an intruder to quickly run in and steal something? The answer
is bollards. Bollards are metal or rock barriers designed to thwart a vehicle-based attack.
When a vehicle hits one of these devices it will be stopped by the bollard and cannot be
used to crash into a building, much like a battering ram.