Introducing Physical Security 403
enough space to hold one occupant. When an individual enters the device and the door
closes, they are required to enter a code or pass visual screening via a camera. Only once
they have been approved are they allowed to enter the secure area through the other door.
In the event that an occupant is denied entry, they are either allowed to exit through
the door they entered or are locked in until security can retrieve them. The intention of the
device is not only to provide security to the environment, but to prevent tailgating and
other forms of access. Figure 17.2 shows a mantrap.
FIGURE 17.2 A mantrap installed in a lobby
Mantraps in some environments are also known as portals. Additionally,
some of these devices include advanced biometric devices, such as retina
scanners and handprint scanners, as well as other features.Locks
Locks come in many types, sizes, and shapes. They are an effective means of physical
access control. Locks are by far the most widely implemented security control due largely to
the wide range of options available as well as the low cost of the devices.