Biometric System Functionality

Biometric System Performance

The factors which can be used to measure the performance of any biometric system are as follows:

• False Accept Rate (FAR)
  Also known as False Match Rate(FMR), it refers to the probability that a biometric system incorrectly accepts an invalid input. Suppose if a person imitates another person and is declared a genuine person by the biometric system based on the matching algorithm, then it is an instance of false acceptance. 
  The FAR also depends on the threshold value set in the system. Lower the threshold value higher the FAR.
   
• False Reject Rate (FRR)
  It refers to the probability by which the biometric system rejects a valid input. It happens when the system fails to determine the match between the input pattern and the matching template stored in the database.
  An example can be when a genuine person’s traits are not identified by a biometric system, thus restricting access.
   
• Equal Error Rate (ERR)
  It is defined as the rate at which both the acceptance and the rejection errors are equal. The accuracy of a system depends on the EER. Lower the EER, the higher the accuracy of the biometric system.
   
• Failure To Enroll (FTE)
  It refers to the rate at which the biometric system fails to create a template from the input provided by the user. In case of poor quality inputs like blurry face or incomplete fingerprint,  FTE is high.
   
• Failure To Capture rate (FTC)
  It is defined as the rate at which the biometric system fails to capture the biometric input though presented correctly. The lower the FTC, the higher is the measurability of the system.
   
• Template capacity
  The maximum number of templates that can be stored on a biometric system is referred to as the template capacity.

Challenges Faced in Biometric System Performance

We know how successfully biometric systems have performed in a number of real-world applications. 

But due to the complex technology involved, there are many challenges too, some of which are as follows:

• Variability
  The input data collected can vary depending upon how the user interacts with the system, change in acquisition device, environment and in rare cases variation in the traits itself. In such a scenario, the biometric system may not perform as expected and thus reducing its efficiency.
  Example - Sometimes the finger scanners of the phone do not recognize the fingerprint due to the wrong way of scanning the fingerprint. 
   
• Accuracy
  There are errors like FRR(False Reject Rate) and FAR(False accept rate) which reduces the accuracy of biometric systems. Ideally, the values of FRR and FAR should be zero and it also depends on the biometric character chosen. Example - Signature scans are more error-prone than retina scans.
   
• Imperfect Data Acquisition
  While taking input data from the user, if the data is not taken properly due to any reason like improper lights for facial scans, injured hands for finger scan etc. then the input data itself is not accurate and hence the goal of the biometric system fails. Therefore, correct data acquisition is important and must be taken care of for the efficient performance of the biometric system.

FAQs

1. What are the two main functions of biometrics?
   The two main functions are biometric matching or verification and access control through biometric identification.
    
2. How is biometric data stored?
   Biometric data can be stored on an end user's device.
    
3. What are the three steps used by the biometric system?
   The process involves three steps: enrollment, live sample and comparison.
    
4. What is a false acceptance rate(FAR) in biometrics?
   The false acceptance ratio (FAR) is a unit used to measure the average number of false acceptances within a biometric security system.
    
5. What is FRR in biometrics?
   False Rejection Rate (FRR) is the average number of times a biometric system fails to grant access to an authorized person.

Key Takeaways

In this article, we have extensively discussed biometric system functionality, performance, factors deciding the choice of biometric character and finally the challenges faced.

We hope that this blog has helped you enhance your knowledge regarding biometric systems, and if you would like to learn more about the ways of ensuring cyber security, check out our articles on:  

• Advantages and disadvantages of the biometric system
• VPN
• Types of Cyber Attackers

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