2 Basic Concepts; User Enrollment; User Verification; Match Threshold - Honeywell VISTA Series User Manual

2 Basic Concepts
This section introduces the definitions and descriptions of the following basic concepts:
Ø
User enrollment
Ø User verification
Ø
Match threshold
Ø
User ID
Ø Authority class
The most important two functions supported by CA­FP­100Fxx series are user enrollment and verification.
2.1 User Enrollment
A user can enroll up to 10 different fingerprints using one ID number to have multiple verification selections.
Theoretically all the fingers of a user need to be enrolled so that the user can still perform fingerprint matching
even if one or more of his/her fingers get cut or damaged. Generally it is recommended that a user shall enroll
at least two fingerprints, for example, the index fingers of both hands, so that the user can use any of the
enrolled fingerprints for recognition even if he/she forgets which fingerprint has been enrolled.
2.2 User Verification
When a user enters a password after placing his/her finger on the fingerprint reader, or scans his/her
fingerprint after entering an ID number, the CA­FP­100Fxx FRT compares the newly scanned fingerprint with
a fingerprint stored in template. The fingerprint template is used to check the user ID. If a user enrolls his/her
fingerprints on an FRT, the user can keep attendance records on this FRT through fingerprint verification
which takes about 2 seconds. Upon verification, the system displays a prompt about whether the verification
succeeds or not and then stores the successful matching record in the CA­FP­100Fxx FRT.
2.3 Match Threshold
The match threshold is set to achieve a trade­off between the possibilities of false rejection and false
acceptance. The false acceptance means the fingerprint recognition device mistakes the fingerprint of user A
for that of user B, while the false rejection means the fingerprint recognition device refuses to recognize an
enrolled fingerprint.
You can set a match threshold for all users. For fingerprints that fail to pass the verification, you can adopt the
"ID + Fingerprint" verification mode (that is, 1:1 match) so that the system adopts the data set in 1:1 match
threshold when matching the fingerprints.
If a user's fingers are severely worn out or damaged, lower the match threshold (see Table 3­1).
Note: The false acceptance rate (FAR) and false rejection rate (FRR) mutually influence each other. Reducing
the FAR will increase the FRR, and vice versa. The default match threshold is 35 and the default 1:1 match
threshold is 15. Table 3­1 lists the settings of match thresholds in different scenarios.
Match Threshold
FRR FAR
High Low
Medium Medium
Low High
2.4 User ID
When enrolling fingerprints, a user will be allocated with an unused ID. When the user starts to verify his/her
identity, this ID is used to associate the fingerprint feature template or password.
Honeywell VISTA Series Products User Manual
1:N
45
35
25
3
Match threshold
1:1
25
15
10