Biometric system

• A biometric system is the technology that recognizes a user's physiological, behavioral characteristics as input, verifies it, and identifies the individual as a unique user.
• Biometric systems rely on specific data about unique biological traits to work effectively.
• To protect the systems and data from unauthorized users biometric systems are used for authenticating and authorizing a person.

General Action Flow of the Biometric system

• Biometric system involves four major steps to identify and verify the authenticated user are as follows:

  • Step 1 - Take real-time biometric input from the user through input sensors.
  • Step 2 - Normalizes the input data and extracts the main features from it by using a processing unit.
  • Step 3 - Compare real-time biometric input with data stored in the database based on algorithms.
  • Step 4 - Finally, shows the result of whether the user is authenticated or not.

Biometric System Workflow

A Biometric system consists of four main components such as input sensors, output sensors or interface, processing unit, and database.

Input Sensors or Interface:

• It is a sensor that takes input from the user in the form of biological data then converted it into digital format.
• Examples -
  • Optical sensor for fingerprint-based biometric systems.
  • Microphone for voice recognition-based biometric systems.
  • Image-Capture sensor for face recognition, retina recognition-based biometric systems.

Processing Unit:

• It is the microprocessor, Digital Signal Processor (DSP), or computer unit that processes the data captured from the sensors.
• This unit processes biometric data collected from the input sensors in a variety of ways as follows:
  • Extracting main features.
  • Normalizing the input data.
  • Comparing input biometric data with stored biometric data in the database.

Database:

• The database stores the biometric samples, which are recalled to perform a matching operation at the time of the authentication process.
• For user identification and verification purposes database can use RAM, Flash EPROM, a data server, or removable storage elements like smart cards.

Output Sensors or Interface:

• It shows the decision of the biometric system to enable access for authenticated users.
• This can be a simple serial communication protocol RS232, a higher bandwidth USB protocol, TCP/IP protocol, Radio Frequency Identification (RFID), Bluetooth, or one of the many cellular protocols.
• It shows bright green color when the user is verified if not then shows bright red color.

Performance Parameters for the Biometric System

Various parameters are used to measure the performance of the biometric system such as follows:

1] False Accept Rate (FAR) -

• It is the proportion that a biometric system will incorrectly identify an unauthorized user as a valid user.
• A lower value of FAR indicates better performance of a biometric system.

2] False Reject Rate (FRR) -

• It is the proportion that a biometric system will incorrectly reject an authorized user as an invalid user.
• A lower value of FRR indicates better performance of a biometric system.

3] Equal Error Rate (ERR) -

• When FRR becomes similar to FAR, the ratio is called the same error rate.
• A lower value of ERR indicates better performance of a biometric system.

4] Genuine Accept Rate (GAR) -

• It is the ratio that a biometric system will correctly identify an authorized user as a valid user.
• A higher value of GAR indicates better performance of a biometric system.

5] Genuine Reject Rate (GRR) -

• It is the ratio that a biometric system will correctly identify an unauthorized user as an invalid user.
• A higher value of GAR indicates better performance of a biometric system.

6] Failure To Capture (FTC) or Failure To Acquire (FTA) -

• It is the ratio of the number of times. A biometric system fails to capture the biometric sample presented to it.
• A lower value of FTA indicates better acquisition performance of a biometric system.

7] Failure To Enroll (FTE) -

• It is the ratio of the number of users that cannot be successfully enrolled in a biometric system and the total number of users presented to the biometric system.
• A lower value of FTE indicates better population coverage.

Application Areas for the Biometric System

• There are multiple areas where biometric systems can be applied such as follows:
  • Banks
  • School and Colleges
  • Offices
  • Hospitals
  • Identifying criminals by forensics
  • Online e-commerce transactions
  • Applying access control to sensitive information and systems
  • Authentic citizenship and immigration systems.