The advent of fast growing technologies makes users to have high security systems with electronic identification options. These identification technologies include ATM and other intelligent cards, user IDsand password based systems, and so on.But,unfortunately these are unsecure due to hacker attacks, thefts, and forgotten passwords.In spite of all these shortcomings and malfunctions these systems are still prevailing; however, the biometric or fingerprint authentication based identification is the most efficient and reliable solution for stringent security.
Introduction to Fingerprint Authentication
This type of identification technology is more reliable, secure and efficient
and uses human physiological processes and behaviors to identifying users’ ID. This biometric-security system is human-oriented system and is more accurate than the traditional password-based systems.This authentication is used in many of the online transactions, confidential financial dealings, industries, offices, institutes, colleges and security access control systems.
A wide variety of finger print devices are available in the market today that varies in cost and method of matching fingers mostly involving one or whole five fingers of the hand. There are various approaches for matching the fingers like matching finger print minutiae, straight pattern matching, moiréfringe and ultrasonic patterns.
Fingerprints form a unique identification pattern for humans, which consist of a pattern of ridges on fingers that helps to grip things by hand.Fingerprint scanner is the heart of this automated authentication system which is responsible for the acquisition of images based on the patterns of ridges and valleys of human fingers, and then matching them with the pre-stored patterns. It consists of sensors that are optical, ultrasonic, thermal, capacitive, etc.,but mostly optical and capacitance scanning methods are used.
These sensors generate top quality images of finger ridges and valleys by overriding inconsistent and irregular designs of the scanned image.These scanners consist of Analog to digital converters which process the analog electric signals to produce digital representation of the image. When we press the finger on a fingerprint scanner, it collects the signals, processes the image and extracts minutiae information of the finger. Subsequently a processing unit or host acquires this ID information and store it in a fingerprint database.
During login, the storage unit compares the pre-stored data and displays appropriate information.For image processing, the digital signal processor or PC is very expensive, but FPGA based hardware is advantageous due to its processing speed, low cost, flexibility and portability. This type of authentication uses special algorithms to compare such fingerprint IDs for effective retrieval of information. For minimizing the power consumption, these systems often get into sleep mode and become active only during fingerprints recognizing mode.
Let us have a look at the practical implementation of fingerprint authentication system using microcontroller to process the data.
Fingerprint Authentication and Controlling System of Devices Using Microcontroller
This type of authentication or identification system is a simple and low-cost system and can be easily implemented with the use of a basic 8051 microcontroller. In this system, the device monitoring and control is performed at a high-level security by authenticating user fingerprints.
The operation of this security system can be easily understood with the above block diagram that consists of power supply, a microcontroller, fingerprint, MAX232, LCD display, relay and alarm blocks. These blocks’ operation is performed from left to right wherein thepower supply block gives entire power to the circuit, and the fingerprint module gives the input to the microcontroller, and then the microcontroller processesthe data and correspondingly drives the buzzer, LCD and relay to operate the loads.
- Fingerprint sensor
- 8051 Microcontroller
- LCD display
- Keil Complier
- Embedded C or assembly language program
- In this project,a fingerprint module is interfaced to a microcontroller with a serial interfacing, and this project uses a relay, a Buzzer, an LCD, and switches.
- 4-pin fingerprint scanners consist of VCC, RX, TX and Ground pins and are connected to 10, 11, 16 pins of the microcontroller, as shown in the figure.
- The LCD is interfaced to thePORT0 of the microcontroller to display the information or data.
- A transistor driven buzzer is connected to the 24-pin of the microcontroller to give alarm for authentication.
- The pushbutton switches are connected to 1, 2, and 3input pins of the microcontroller for informing about the type of operation to themicrocontroller including scanning, adding and deleting fingerprint.
- The relay is connected to the25th pin of the microcontroller through a transistorto operate the loads or devices.
- The Microcontroller is programmed in embedded C language in Keil software and this hexa code is dumped to the microcontroller using a hardware circuitry.
- In this circuit, for powering the entire circuit, mains AC supply at 230V is stepped down to 12V AC, rectified to DC, filtered and regulated to circuit operating range 5V. This power block is not given in the above circuit for not making a whole circuit complex.
- For required operation by user like identifying, adding and deleting finger, an appropriate switch has to be pressed. For certain button pressing, the microcontroller processes the fingerprint images.
- When a person presses the finger on fingerprint scanner, itgives high and low-logicdigital signals to the microcontroller after pressing switch2. This controller is programmed in such a way that it stores the digital data.
- When the switch1 is pressed, again it ask for fingerprint scanning;if this data matches with the previously stored fingerprint data, it generates an output signal tothe transistor and also displays the informationon theLCD display.
- If the transistor isactivated, it automatically energizes the relay coil, and thus the relay gets operated and the corresponding device is turned on.This also gives an alarm from a buzzerupon authenticating the fingerprint.
- It is also possible to delete the scanned finger by pressing the switch3, and also, if any unauthorized person tries to access the device, this system gives an alarm. This system can be implemented at homes since it is affordable to generate home alarm system.
This type of authentication for controlling devices and appliances is highly secured and more reliable at a lower cost due to inexpensive microcontroller. Thus, you might have got an idea of implementing a fingerprint authentication system by using a simple controller. This can also be implemented as an attendance system in schools and offices by adding external memory. If you have any doubt on implementing this circuit, you can contact us by commenting below.