Environmental Engineering Reference
In-Depth Information
as unique biometric identifiers for individuals. Biometric systems recognizing
fingerprints, palm shape, eyes, face, voice, and signature comprise the bulk of
the current biometric systems. Biometric security systems use biometric tech-
nology combined with some type of locking mechanisms to control access to
specific assets. To access an asset controlled by a biometric security system, an
individual's biometric trait must be matched with an existing profile stored in
a database. If a match between the two is identified, the locking mechanism
(e.g., a physical lock at a doorway or an electronic lock at a computer terminal)
is disengaged, and the individual is given access to the asset. A biometric
security system is typically comprised of the following components:
• A sensor measures and records a biometric characteristic or trait.
• A control panel serves as the connection point between various sys-
tem components. The control panel communicates information back
and forth between the sensor and the host computer and controls
access to the asset by engaging or disengaging the system lock based
on internal logic and information from the host computer.
• A host computer processes and stores the biometric trait in a
database.
• Specialized software compares an individual image taken by the
sensor with stored profiles.
• A locking mechanism is controlled by the biometric system.
• A power source supplies power to the system.
Biometric Hand and Finger Geometry Recognition
Hand and finger geometry recognition is the process of identifying an indi-
vidual through the unique geometry (e.g., shape, thickness, length, width)
of that individual's hand or fingers. Hand geometry recognition has been
employed since the early 1980s and is among the most widely used biometric
technologies for controlling access to important assets. It is easy to install
and use and is appropriate for any location requiring highly accurate bio-
metric security; for example, it is currently used in numerous workplaces,
daycare facilities, hospitals, universities, airports, and power plants.
A newer option within hand geometry recognition technology is finger
geometry recognition (not to be confused with fingerprint recognition).
Finger geometry recognition relies on the same scanning methods and tech-
nologies as does hand geometry recognition, but the scanner scans only two
of the user's fingers, as opposed to the entire hand. Finger geometry recogni-
tion has been in commercial use since the mid-1990s and is mainly used in
time and attendance applications (i.e., to track when individuals have entered
and exited a location). To date, the only large-scale commercial application of
two-finger geometry for controlling access is at Disney World, where season-
pass holders use the geometry of their index and middle finger to gain access
to the facilities.
