ALTERED FINGERPRINT ANALYSIS

8/13/2019 ALTERED FINGERPRINT ANALYSIS

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ALTE

FINGERPR

DETECTIONANAL

By-


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Definition of Biometrics

Automated methods of recognizing a person based on a phy

behavioral characteristics.

The technology used for identification of a user based on a

behavioral characteristic, such as a fingerprint, iris, face, voice o

is called Biometrics.


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History of fingerprintsA fingerprint in its narrow sense is an impression left by the friction ridgehuman finger.

Human fingerprints have been discovered on a large number of archaeolohistorical items

In 1684, the English plant morphologist, Nehemiah Grew, published the freporting his systematic study on the ridge, furrow, and pore structure

In 1788, a detailed description of the anatomical formations of fingerprint

Mayer.

In 1823, Purkinji proposed the first fingerprint classification, which classicategories

In1975, The FBI funded the development of fingerprint scanners


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Fingerprint Recognition

Fingerprint recognition or fingerprint authentication refers to the autoof verifying a match between two human fingerprints. Fingerprints a

forms of biometrics used to identify individuals and verify their iden

The analysis of fingerprints for matching purposes generally requires

comparison of several features of the print pattern. These include pat

aggregate characteristics of ridges, and minutia points, which are unifound within the patterns. It is also necessary to know the structure a

human skin in order to successfully employ some of the imaging tech


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Fingerprint Patterns

Arch- The ridges enter from one side of the finger, rise in th

forming an arc, and then exit the other side of the finger.Loop-The ridges enter from one side of a finger, form a curv

exit on that same side.

Whorl-Ridges form circularly around a central point on the f

Arch Loop Whorl


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Different Identification on Fingerprin

Crossover: two ridges crosseach other

Core: centre

Bifurcation: ridge separates

Ridge ending: end point

Island: small ridge b/w two

spacesDelta: space between ridges

Pore: human pore


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Fingerprint matching techniques

There are two categories of fingerprint matching techniques:

Minutiae-based: Minutiae-based techniques first find minutiae points and then map

relative placement on the finger.However this technique is not capable of dealing wi

quality images.

Correlation based: The correlation-based method is able to overcome some of the d

of the minutiae-based approach. The correlation based fingerprint verification first

appropriate templates in the primary fingerprint,uses template matching to locate t

the secondary print,and compares the template positions of both the fingerprints.


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Two main technologies used to capture

of the fingerprint

Optical sensoruse light refracted through a prism. An optical sensor

uses light to read and acquire fingerprint images. Optical sensors can be

a number of real life factors such as stray light, surface contamination or

fingerprint impressions present on the sensor surface. Hence it is essen

the fingerprint reader glass on a regular basis for optimal performance.

Capacitive sensordetect voltage changes in skin between ridges andCapacitive sensors use electric current to sense a fingerprint and captur

As sensors apply a small voltage to the finger, a real fingerprint is requir

than a visual impression of it. This technique makes the fingerprint reade

reliable as it becomes harder to fake enrollment.


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Image Processing

Capture the fingerprint images and process them throu

series of image processing algorithms to obtain a clearunambiguous skeletal image of the original gray tone imp

clarifying smudged areas, removing extraneous artifacts

healing most scars, cuts and breaks


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Advantage of Fingerprints

a. Very high accuracy.b. It is the most economical biometric user authentication tecc. Easy to use.d. Small storage space required for the biometric template, resize of the database memory requirede. It is standardized.

Why are fingerprints unique?

The answer is because development of fingerprints is both gand environmentally influenced. Within a basic pattern predeour genes, fingerprints of each individual form in a way that isdifferent from anyone else. Even identical twins have unique


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Fingerprint AlterationThe widespread deployment of Automated Fingerprint Identification Systems

enforcement and border control applications has heightened the need for ens

these systems are not compromised. While several issues related to fingerpr

security have been investigated, including the use of fake fingerprints for ma

identity, the problem of fingerprint alteration or obfuscation has received veryattention.

The problem involving altered fingerprints falls under a broader category of a

as biometric obfuscation. Obfuscation can be defined as a deliberate attemp

individual to mask his identity from a biometric system by altering the biomet

its acquisition by the system. Fingerprint obfuscation refers to the deliberate

the fingerprint pattern by an individual for the purpose of masking his identity

Photographs of altered fingerprints. (a) Transplanted friction ridge skin from sole . (b)that have been bitten . (c) Fingers burnt by acid . (d) Stitched fingers.


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Altered fingerprints, are real fingers that are used to concidentity in order to evade identification by a biometric syste

Altered fingerprints are different from fake fingerprints.Why is detection of altered fingerprints needed?

1) Fingerprint-based biometric systems are much more

for large scale identification than any other biometric

2) It is relatively easy to alter ones fingerprints using ch

and abrasives compared to, say, ones iris or face,

where a more elaborate surgical procedure may be n

3) Mutilated fingerprints are being routinely

encountered by law enforcement and immigration

officials in several countries, thereby underscoring th

urgency of finding a solution to this problem.


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Types of Altered Fingerprints1) Oblit eration: Friction ridge pattern on fingertips can be ob

abrading, cutting, burning applying strong chemicals, and tran

smooth skins. Further, factors such as skin diseases and side

cancer drugs can also obliterate the fingertips. If the damage the generating layer in the epidermis, the skin will generate to

pattern after a few months time. However if the damage is do

generation layer, scar tissues instead of well defined ridge de

the damaged area. If the affected finger area is small, automa

successfully matching the damaged fingerprints with original m

fingerprints.


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2)Distor t io n: By using a plastic surgery friction ridge pattern

unusual ridge pattern. Some portion of skin are removed from

grafted back in to different position resulting a unusual patternfig below. As distorted images may have the sufficient image

pass the automated fingerprint identification system.


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3)Imitat ion: Here the surgical procedure is performed in such

altered finger prints appear as natural fingerprints. The surger

large area of the fingertips. But if the area of alteration is smadefeat the AFIS. The main clue to detect the transplanted fing

presence of surgical scars.


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ALTERED FINGERPRINT ANALYSIS

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