Biometrics - Buro Jansen & Janssen

3.3 Security Procedures
Biometrics is usually used as a security procedure. This can be classified into enrolment and
authentication [Fleming, S.T., p.120, 2003].
Enrolment
During the enrolment phase, biometrics is obtained and linked to an identity of an
individual. The identity is encoded and can now be stored, retrieved and matched. Some
biometric devices store the data locally within the device itself. Individuals must enrol and
authenticate with the same device. Other biometric systems allow the enrolled biometric
data to be stored in a database that can be accessed from multiple locations. For example
there are various controlled entry points, and there are many devices distributed over a
wide area and many potential users. In this case the device allows retrieving the biometric
data from a database and then performs comparisons. Data can be retrieved by a sensory
device for example a fingerprint scanner, and the distinctive biometric characteristic can be
identified.
Authentication
Authentication is the process of an individual claiming to have a certain identity. New
information is compared to the stored data. Authentication can take place in two different
ways: identification and verification.
Identification
Identification is when an individualʹs biological features are searched within a data set.
This is a one‐to‐many search. For example if fingerprints are found at a crime scene, they
are compared to fingerprints of all known delinquents stored in databases. The system
returns all the closest matches to the individual. Identification is usually performed in a
non‐invasive context.
Verification
Verification occurs when someone claims to have a particular identity, for example to gain
access to a high‐security area. The biometric system compares the newly scanned data to a
previously stored version. Thus the userʹs identity is then validated biometrically. This is a
one‐to‐one search process. A direct comparison between the userʹs features and the data are
matched. With a certain error margin it allows for minor temporal factors or sensor
discrepancies.
As a general rule verification systems are considerably more accurate than identification
systems, primarily because one‐to‐one comparisons are technically simpler than one‐to‐
many.
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