25,May 2024
Fingerprints have been used since years to determine the identity of an individual. Instead of being an important pillar in the crime investigation method, we know a few things only about the factors that influence the print patterns of a person. According to scientific studies, we came across the fact that these prints are affected by both genetic and environmental factors. The fingerprints of a person are based on the skin ridge patterns known as dermatoglyphs present on the fingertips. These pattern making ridges are also present at the toes, palms, and soles of the feet. Here in this blog, we have explained the science behind the fingerprints and the factors that make them unique in nature.
How fingerprints are formed?
The patterns known as fingerprints develop before the birth of a person and remain same throughout the life. The ridges and furrows present on the fingers starts developing during the third and fourth month of the fetal development itself and attain full form by the sixth month of the pregnancy. However, we do not know the exact function of these ridges but it is being speculated that the sensitivity of touch is influenced by them.
The shape, size, and the space of these patterns known as dermatoglyphs are influenced by the genetic factors and since multiple genes are involved in this process hence these patterns are not inherited by an individual directly. The development of the skin layers, and muscles, and blood vessels play a major role in defining ridge pattern.
Factors that affect formation of fingerprints:
These prints are affected by several factors as we have mentioned earlier as well. These factors are genes of father and mother and the environment of mother’s womb. Here we have discussed the impact of both these factors on the formation and growth of fingerprints.
Effect of mother’s womb on fingerprints:
The womb of a mother affects the print formation of a new born to a larger extent. A small variation in the environment of the womb can lead to huge changes in the print patterns. The factors that cause the formation and changes in the patterns are given below:
- Level of nutrition present in mother’s womb,
- The umbilical cord’s length,
- The amount of blood flow present in the womb,
- Mother’s blood pressure,
- The Position of fetus,
- Growth rate of bones,
- Growth of limbs and fingers.
Effects of genes on fingerprints:
Apart from the factors present in the womb of a mother, other factor that defines the kind of patterns these prints have are defined by the effect of genes. Here we have mentioned the genetic factors that affect the fingerprints formation:
- Impact of Bone Morphogenetic protein (BMP) on the finger ridges,
- Impact of Wingless related integration sites (WNT) on ridges.
Bone Morphogenetic protein (BMP) slows down the growth of the ridge formation on the fingers while Wingless related integration sites (WNT) enhances the growth of these ridges. Because of one force reducing the growth of ridges and another force trying to increase the ridge formation rate a friction appears and thus leads to the creation of unique ridges. This force forms strips on the fingertips and are known as whorls. And because the rate of force applied on the ridges is variable in each individual the fingerprints formed are unique. And therefore no one have same set of fingerprint patterns and not even twins can have matching or identical prints.
How Fingerprints are used in biometric recognition?
Fingerprint biometric recognition systems analyze minute details of the print patterns like how the ridges are bifurcated or how they end on the fingertips. To use the prints as recognition factor the data of the prints are initially stored in the database after capturing them with necessary devices. In order to capture the fingerprints visible light is used for optical capture, while current is passed through the fingers to measure it using capacitive sensors.
There are two types of sensors that are used to capture the image of ridge patterns are contact sensors and contactless sensors. Contact sensors collects the data of ridge pattern by coming in contact with the sensors while contactless takes 2D or 3D image of the ridge pattern by keeping the sensor away from the fingers.
The principle behind use of fingerprints in the identification of an individual is the distinctiveness of the ridge outlines that are present on the end joints of the fingers and thumbs. Because of definite contours present on the ridges they appear in several patterns hence gives unique identity to individuals. Fingerprints are infallible and most feasible method of identification since other identification methods have caused several mistakes in the identification.
Myths associated with fingerprint science:
Though fingerprints are used widely for the purpose of human identification and to make major revelations about an individual, there are still many myths associated with the science of fingerprints. Some of the most common myths that are related with fingerprint science are given below:
- Fingerprints are Eternal:Though the fingerprint patterns are eternal but the impressions made by these prints are not forever and because of skin conditions or other genetic conditions often known as Adermatoglyphia causes distortion of these prints. For example, people who work as typists, clerks, or people engaged with message work, house maids lose their prints and the characteristics of such patterns fade away with time.
- DNA Overshadows Fingerprint Science:Since criminals are smart enough to erase the blood stains or body fluids, fingerprints still remains one of the most reliable sources of identification. It is because of the fact that the objects or the articles present at the crime scene are touched by the criminals for sure while committing crime. So these prints are easily collected by the investigators as well for the purpose of examination and hence can be used for the verification of suspects of the case by the law enforcement agencies.
- Only Humans Have Fingerprints:It is being considered that only humans are the animals that have fingerprints but it is not right. You must be aware of the fact that animals like gorillas, chimpanzees, etc also have fingerprints and that too unique in nature.
- System Are Enough To Reveal Latent Prints:There is a widespread misconception that Automated Fingerprint Identification System (AFIS) like systems are enough to dig out the required information of the individuals and no physical work is required to be done by the forensic science experts to study the patterns. But it is not true and to work on the identification of the individuals, experts do a lot of hard work and the task demands their expertise.
How criminals break fingerprint authentication?
To break the authentication factor of the fingerprint biometric security, criminals use several methods. Some methods or techniques used by them are easy to crack while there are some that becomes difficult to figure out and solve the mystery. Some of the methods used by such criminals are as follows:
1. Attacks:
In this case, the attackers simply use their own fingers on the sensor surface and wish to be recognized as identified user in the database. In such attacks, the success rate is very low and hence people fail to attain what they wanted to.
2. Artefacts:
Those attackers who are trained try to make an artifact, known as false fingerprint that matches the print patterns of an enrolled user of the database. Once an artifact is successfully produced, now the chances of defeating the secured system are least and hence criminals are successful in their attempt.
If your are wondering how artefacts are made then it is not a difficult task and such videos elaborating the stepwise procedure for doing so can be found easily on the internet.
Problems associated with fingerprint system:
The science of fingerprint might seem to be simple but there are a lot of problems associated with this system. And therefore we have seen in many organizations such biometric authentication is not used. One of the most important issues related with this system is enrolment problem.
It is not easy for entire population to be able to provide adequate samples required for the biometric purpose that will be used for the system. This unavailability is because of lack of literacy rate among the people. And because of this low quality biometric samples are collected which can’t furnish enough information about an individual.
Protections used in fingerprint systems:
Since we are aware that the security threats are higher in case of fingerprint biometric system therefore it becomes quite important to protect the systems as well. And to make sure the systems are secured properly the experts indulged in this system uses various methods to secure the data. Following checks can be done on the biometric sensor and controlling software to detect a attacks:
- Sub-dermal analysis of the image,
- Deformation effects,
- Optical spectrum analysis,
- Conductivity of the skin,
- Oxygen levels of the blood present in the finger,
- ECG measurements.
Fingerprints are playing an important role in the field of forensic science in identification of the suspects and the victims of case and will continue to do so because of their uniqueness.
References:
- https://www.forensicsciences implified.org/prints/
- https://www.nist.gov/forensic -biometrics#:~:text=Fingerprint %20analysis%20generally%20 involves%20comparing,assessing %20how%20similar%20they%20 are
- https://www.azolifesciences .com/article/Fingerprint-Analysis -in-Forensic-Science.aspx
- https://www.forensicsciences implified.org/prints/how.html
- https://www.fingerprintexpert .in/blog-details/fingerprint- analysis-and-examination