Zodiac Link
Page 27 of 32
Operator Guide
June 2012 • Rev. 1.2
Fingerprint Enrollment Overview
When a user places his/her finger on the fingerprint scanner for the first
time, the fingerprint is scanned and a 3-D fingerprint image is captured. All
fingerprints contain a number of unique physical characteristics called
minutiae, which include certain visible aspects of fingerprints such as ridges,
ridge endings and bifurcation (forking) of ridges. Most of the minutiae are
found in the core points of fingerprints, and the core points themselves are
found near the center of the fingerprint on the fleshy pad. The illustration
below shows the positions of core points within fingerprints.
When a user is enrolled, a special minutiae-based algorithm extracts key
minutiae points from the live image at the time of acquisition and converts
the data into a unique mathematical template comparable to a 60-digit
password. This unique template is then encrypted and stored within the user
record in the Zodiac Link controllers. It is important to note that
no actual
image of the fingerprint is stored
, only the minutiae-based template.
FACTORS AFFECTING ENROLLMENT
The quality of a fingerprint image is relative to the number of minutiae
points captured. If the number and locations of the minutiae remain
consistent whenever an individual’s fingerprint image is scanned and
captured, the fingerprint image is successfully matched to the pre-existing
template. Fingerprint images that do not possess an adequate number of
minutiae points may be unusable.