Fingerprint Biometrics: Definition and How Secure It Is

Fingerprints are a unique feature that every person has, and no two people have the same ones. Fingerprint biometrics is used to both authenticate (match a person’s biometric template) and identify (determine the identification of a person). 

A person’s unique physical characteristics are called biometrics, which can be used to validate and verify identity. 

Fingerprint biometrics is some of the most commonly used types of biometrics for authentication and identification purposes, but facial recognition, iris scanning, and DNA are all forms of biometric identifiers as well. Fingerprint biometrics is widely distributed, cost-effective, easy to use, effective, hard to fake, and convenient, making them a secure and useful tool for authentication and identity verification.

Understanding fingerprint biometrics

Biometric technology uses unique physical or behavioral attributes that are individual and not replicable. 

Fingerprints are a method of identifying a person, and they are specific to each individual. No one else will have the same fingerprints that you do. Fingerprints are made up of specific patterns, including ridges, valleys, arches, loops, and whorls. 

For the purposes of proving identity, there are three main methods used:

• Something you know, like a password
• Something you possess, such as a token or keycard
• Something you are, including fingerprints, face, or hand

Fingerprint biometrics involves something you are. You always have your fingerprints on you, and they belong to you alone. Fingerprint biometrics has been used for decades with recent technology becoming more and more advanced, allowing for a more technical and widespread use of this important tool.

Biometric authentication & security

Biometrics uses a statistical analysis and measurement of physical or behavioral characteristics as a security feature to authenticate and identify an individual. Fingerprint biometrics can be a frictionless form of security that is easy and seamless to use. 

Fingerprint scanners can be used to secure physical access to locations as well as to devices. Fingerprint biometrics is a security feature that cannot be forgotten or misplaced like a password or hardware token.

Biometric security can be more secure than other forms of authentication, as biometric information is linked to a specific individual and therefore more difficult to steal, lose, or compromise. This can improve reliability and simplify security processes.

There are some flaws to fingerprint biometrics, however, and cybercriminals can find ways around this form of security. If the wrong person enters their fingerprints matched to your data, for example, it is harder to invalidate these biometric authentication details. 

Also, if someone does gain access to your fingerprint data, which is left anywhere you touch and can be fairly easily obtained, this data is not changeable. You cannot change your fingerprints, so replicas will be able to access anything that is fingerprint-protected. 

Master fingerprints have been able to “fool” smart devices, and software flaws can present issues for fingerprint biometric security.

How fingerprint biometrics work

Fingerprint biometrics uses some form of a scanner to obtain an image of your fingerprint. Methods include the following:

• Optical scanner: This takes a digital image of your fingerprint by lighting up the finger through a prism and reading the way the ridges and valleys reflect the light. This information is then converted into an image.  
• Capacitive scanner: This generates a small electric charge through miniature built-in capacitors that store electricity. The capacitors are discharged when the finger touches the scanner.

A higher level of discharge is created by fingerprint ridges, which have a greater contact surface, and less by the valleys, which create gaps in the skin. The difference between these is measured to determine a pattern.  

• Ultrasound scanner: An ultrasound signal is used to record the echo the fingerprint creates, as ridges and valleys create different echoes. This scanner does not need to be in direct contact with the finger to get a reading and also has the benefit of reading in a more three-dimensional manner.  
• Thermal scanner: This uses heat to measure the temperature difference between the ridges and valleys of the fingerprint. It creates the image of the fingerprint based on the contrast between the two.

After fingerprints are scanned, they can then be matched based by pattern matching, which compares two images looking for similarities. More commonly, minutiae-based matching is used, which looks more closely at the direction and location of the points.

The unique data and specific characteristics of the fingerprint are filtered and then saved as a mathematical representation (algorithm) or as an encrypted biometric key. The fingerprint image itself is not saved, only the binary code (or series of numbers) is retained and used for verification purposes. This algorithm cannot be reverse engineered to recapture the image of the fingerprint and thus cannot be duplicated. 

Fingerprint data is generally stored on the device itself and not in the cloud.

Benefits of fingerprint biometrics

Overall, fingerprint biometrics is considered to be highly secure and a common method of protection. For the highest level of security, they can be used as part of a dual or multi-factor authentication (MFA) model that includes the use of at least one other method as well, such as a password or token.

Benefits of fingerprint biometrics include the following:

• Fingerprints cannot be lost or misplaced, and they are always with the person.
• Fingerprints are hard to fake and more secure than a password or token.
• Fingerprint patterns cannot be guessed and are non-transferable.
• Fingerprint biometrics offers a high level of security for identity verification.
• Fingerprint biometrics is user-friendly and convenient.
• Fingerprint biometrics is easily deployable and cost-effective.
• Use of fingerprint biometrics can provide accountability.
• Fingerprints take work to steal or spoof.
• Fingerprint biometric techniques are fast, simple, and easy to use.

Where fingerprint biometrics is used

Biometric technologies, and fingerprint biometrics specifically, are used across a wide variety of fields and industries for the purpose of authentication and identity verification. These are examples:

• Law enforcement and public security: Fingerprints are a common method of identifying suspects and criminals. The IAFIS (Integrated Automated Fingerprint Identification System) is the national computerized system that stores, compares, and exchanges digital fingerprints for the purpose of matching them to a known party in the database.  
• Military: Fingerprint identification can be used to identify non-U.S. citizens on the battlefield, to help determine military allies and enemies. The Defense Forensics and Biometric Agency (DFBA) stores biometric information, including fingerprints as a matter of national security.  
• Border control and travel: The Department of Homeland Security (DHS) runs the Automated Biometric Identification System (IDENT) to store and process biometric information, such as fingerprints for immigration and border control, intelligence, background information for national security clearances, law enforcement, and for the purposes of national security.

DHS also issues e-Passports in the United States to be used for international travel, which contain an electronic chip that holds biometric information of the holder, like fingerprint data. Airport security can also use fingerprints and other biometrics to authenticate travelers.  

• Health care: Biometric ID cards containing fingerprints can be used to access health care services and resources to ensure the right person is receiving treatment. Hospitals, pharmacies, and clinics also often have fingerprint scanners to match a patient to their patient records.  
• Facilities: Fingerprint biometrics can be a form of physical access control used by companies and organizations to grant and deny access to actual locations based on who a person is and not what they have or know.  
• Computer systems and networks: Smartphones, laptops, and computers all often use a form of biometrics, such as a fingerprint, to unlock them, granting access to only that specific user. This is called logical access control.

Fingerprint data is stored directly in the device itself, making it more secure and less prone to potential privacy issues or data breaches.  

• Commercial applications: Many different commercial and retail industries use fingerprint biometrics to verify a customer’s identity and authenticate a user. Banks and financial institutions can require fingerprint access for transactions, for example, as can credit card readers or retail establishments.

Fingerprint biometrics can be used to authenticate a person based on matching the data within a system, or it can be used as a method of identity verification to ensure that a person is who they say they are. Fingerprint biometrics can add an extra layer of security over password and token security measures. 

Fingerprint scanners are dropping in price, making them more widely available and accessible for a wide range of businesses, organizations, and industries.

Key takeaways

Fingerprint biometrics is a commonly used form of biometric security that is easy to use, hard to fool, and often a cost-effective strategy, relying on something a person has. Fingerprints cannot be forgotten or lost like a password or ID card, and no two people share fingerprints, guaranteeing that they are unique to each individual. 

Fingerprint biometrics use a scanner that can be small and freestanding or contained within a device directly, such as a smartphone, security system, or computer. Fingerprint scanners take a digital rendering of the fingerprint and convert it to a digital algorithm for storage. 

In this way, fingerprint data is safe from reverse engineering. Even if a bad actor obtains the fingerprint data through a breach or theft, it cannot be turned back into the fingerprint image and used.

A security feature that is convenient, easy to use, and user-friendly, fingerprint biometrics is used across a wide range of applications to both verify and authenticate identities. 

Biometrics is a growing field as well, and the use of biometric identifiers, such as facial recognition, iris scans, and behavioral biometrics including typing patterns, online interactions, and device handling, are all being explored for even more uses than they are used for today. Biometrics can offer a high level of security that is unique to the individual user and harder to compromise. 

Fingerprint biometrics continue to advance with evolving technology. More companies and industries are adopting this form of biometric authentication. When coupled with other security protocols, such as strong passwords or tokens, fingerprint biometrics are even more secure.

References

“No Two Fingerprints are Alike.” (2022). Rutgers. 

Biometric Security Systems: A Guide to the Devices, Fingerprint Scanners and Facial Recognition Access Control. (August 2020). IFSEC Global. 

Privacy Impact Assessment Integrated Automated Fingerprint Identification System National Security Enhancements. Federal Bureau of Investigation (FBI).

DFBA Overview. (2021). Defense Forensics & Biometrics Agency.

DHS/OBIM/PIA- 001 Automated Biometric Identification System. (November 2019). Department of Homeland Security (DHS).

E-Passports. Department of Homeland Security.