Fingerprint Scanner Technology [Detailed]

Fingerprint scanners are security systems of biometrics.They are now used in offices,security industries and most recently,on computers and mobile phones.Everyone has marks on their fingers.They can not be removed or changed.These marks have a pattern and this pattern is called the fingerprint.

Well,well,well After reading the aboved definition many of you might have a question that what is biometrics......

Biometrics are automated methods of recognizing a person based on a physiological or behavioral characteristic.

Among the features measured are face,fingerprints,hand geometry,handwriting,iris,retinal,vein and voice,Biometric data are separate and distinct from personal information.

Biometric templates cannot be reverse-engineered to recreate personal information and they cannot be stolen and used to access personal information.

Using a unique,physical attribute of your body such as your fingerprint or iris to effortlessly identify and verify that you are who you claim to be is the best and easiest solution in the market today.That is the simple truth and power of Biometrics Technology today.

Although biometric technology has been around for many years,modern advances in this emerging technology, coupled with big reductions in cost,now make biometrics readily available and affordable to consumers,small business owner,larger corporations and public sector agencies.

Now you guys know what biometrics is,lets learn more about the fingerprint scanner.

How it works:

Earlier only the top tier or high end phone's used to have the fingerprint scanner but nowadays th mid-range or the budget phones are equipped with a fingerprint scanner,so how it works and what type of finger print scanner are available let's see.....
Generally there are 3 types of fingerprint scanner and they are,

1. Optical scanner
2. Capacitive scanner
3. Ultrasonic scanner

We will only look in details about the capacitive scanner as it is the one which is commonly used but i'l also give a general explanation about the other two scanner's.

Optical scanner:

- Optical fingerprint scanners are the oldest method of capturing and comparing fingerprints,
- A fingerprint scanner system has two basic jobs,it needs to get an image of your finger and it needs to determine whether the pattern of ridges and valleys in this image matches the pattern of ridges and valleys in pre-scanned images.
- Only specific characteristics, which are unique to every fingerprint are filtered and saved as an encrypted biometric key or mathematical representation.No image of a fingerprint is ever saved only a series of numbers (a binary code) which is used for verification.The algorithm cannot be reconverted to an image,so no one can duplicate your fingerprints.
- As the name suggests,this technique relies on capturing an optical image,essentially a photograph and using algorithms to detect unique patterns on the surface,such as ridges or unique marks by analysing the lightest and darkest areas of the image.
- The major drawback with optical scanners is that they aren’t difficult to fool.As the technology is only capturing a 2D picture,prosthetics and even other pictures of good enough quality can be used to fool this particular design.
- With increasing demand of tougher security smartphone companies have adopted superior capacitive scanners.

Capacitive scanners:

- The most commonly found type of fingerprint scanner used today is the capacitive scanner.As the name suggests the core component used here is a capacitor.Instead of creating a traditional image of a fingerprint,capacitive fingerprint scanners use arrays tiny capacitor circuits to collect data about a fingerprint.
- As capacitors can store electrical charge connecting them upto conducting plates on the surface of the scanner allows them to be used to track the details of a fingerprint.
- The charge stored in the capacitor will change slightly when a finger's ridge is placed over the conducting plates,while an airgap will leave the charge at the capacitor relatively unchanged.
- An op-amp integrator circuit is used to track the changes,which can be then recorded by an analog to digital converter.

- This technique is much tougher to fool as compared to the optical scanner due to its sophisticated design as different materials will record slightly different changes in charge at the capacitor.
- Creating a large enough array of these capacitors,typically hundreds in a scanner,allows for a highly detailed image of the ridges and a valley of a fingerprint to be created from nothing more then electrical signals,More capacitor results in a higher resolution scanner,increasing the level of security upto a ceratain level.
- The only security risk arises from either hardware or software hacking.
- Due to large numbers of components used in the detention circuit,capacitive scanners can be a little costly,hence swipe scanners where used i.e. less number of capacitors components were used by quickly refreshing the results as soon as a finger is pulled over the sensor.
- These days,the simple press and hold design are most commonly used.

Ultrasonic Scanner:

- This is the latest fingerprint scanning technology till date which uses an ultrasonic sensor.
- The details of the fingerprints are captured with the hardware consisting of ultrasonic transmitter and receiver.
- An ultrasonic pulse is transmitted against the finger that is placed over the scanner,some of these pulse are absorbed and some of it bounces back to the sensor,depending upon the ridges,pores and other details that are unique to each fingerprint.
- There is no microphone listening out for those returning signals,instead a sensor that can detect mechanical stress is used to calculate the intensity of the returning ultrasonic pulse at different points on the scanner.
- If its scanned for a long period of time ,additional depth of data is captured,resulting in highly detailed 3D reproduction of the scanned fingerprint.
- The 3D nature of this capture technique makes it an even more secure alternative to capacitive scanners.