BIOMETRICS

BIOMETRICS 

 Biometrics is the science and technology of measuring and analyzing biological data. In information technology, biometrics refers to technologies that measure and analyze human body characteristics, such as DNA, fingerprints, eye retinas and irises, voice patterns, facial patterns and hand measurements, for authentication purposes.

Biometric devices, such as fingerscanners, consist of:

• A reader or scanning device
• Software that converts the scanned information into digital form and compares match points
• A database that stores the biometric data for comparison

The following are used as performance metrics for biometric systems:

• False Accept Rate or False Match Rate ( FAR or FMR ): the probability that the system incorrectly matches the input pattern to a non-matching template in the database. It measures the percent of invalid inputs which are incorrectly accepted.
• False Reject Rate or False Non-match Rate ( FRR or FNMR ): the probability that the system fails to detect a match between the input pattern and a matching template in the database. It measures the percent of valid inputs which are incorrectly rejected.
• Receiver Operating Characteristic or Relative Operating Characteristic ( ROC ): The ROC plot is a visual characterization of the trade-off between the FAR and the FRR. In general, the matching algorithm performs a decision based on a threshold which determines how close to a template the input needs to be for it to be considered a match. If the threshold is reduced, there will be less false non-matches but more false accepts. Correspondingly, a higher threshold will reduce the FAR but increase the FRR. 
• Equal Error Rate or Crossover Error Rate ( EER or CER ): the rate at which both accept and reject errors are equal. The value of the EER can be easily obtained from the ROC curve. The EER is a quick way to compare the accuracy of devices with different ROC curves. In general, the device with the lowest EER is most accurate.
• Failure to Enroll Rate ( FTE or FER ): the rate at which attempts to create a template from an input is unsuccessful. This is most commonly caused by low quality inputs.
• Failure to Capture Rate ( FTC ): Within automatic systems, the probability that the system fails to detect a biometric input when presented correctly.
• Template Capacity: the maximum number of sets of data which can be stored in the system.