Biometric Authentication: A Comprehensive Guide

As traditional methods of safeguarding sensitive information continue to face evolving threats, the need for more advanced and reliable authentication techniques has become imperative. This is where biometric authentication steps into the spotlight.

In 2020, approximately 80% of active phones in North America, Western Europe, and Asia Pacific featured biometric authentication systems. By 2022, the global biometric system market had already reached a valuation of approximately 43 billion U.S. dollars, with expectations of doubling in size by 2027.

But what is biometric authentication, how does it work, and is it actually that safe? Let’s find out before you can decide if that’s the right authentication method for your app, website or software.

What is biometric authentication?

Biometric authentication (or biometrics) validates a person’s identity based on their unique physical or behavioral characteristics, like fingerprints, facial features, eyes and voice. Over the past decade, biometrics have become an integral part of our daily lives. They enable users to unlock their phones, make secure payments, and access sensitive information with a simple touch or glance.

When implemented effectively, biometric authentication offers enhanced security and convenience compared to traditional knowledge-based methods like passwords and PINs.

How biometric authentication works

To illustrate how biometric authentication works, consider the example of a smartphone with a fingerprint scanner. Typically, there are three essential components:

Sensor

In this scenario, the sensor is the fingerprint scanner integrated into the phone. The sensor employs capacitive scanners to read the electric currents generated by an individual's unique fingerprint.

During initial setup, conductor plates on the scanner's surface capture the ridges and valleys of the fingerprint, converting it into digital data known as a fingerprint template, which is stored locally on the user's device.

Storage

Most smartphones offer secure local storage for the fingerprint template during verification. This stored template lets the system confirm whether the user requesting access matches the one whose fingerprint template is stored on the device.

Processor

The processor is a computing device that compares the captured fingerprint scans from the sensor with the fingerprint template stored in the database.

This video from the Visa security team explains the process in greater detail.

Types of biometric authentication

There are multiple types of biometric authentication in use today, with ongoing research to develop new and more sophisticated approaches. The most prominent types include fingerprints, facial anatomy, iris/retina scans, and voice authentication.

Fingerprints

Fingerprint authentication uses the unique ridges and patterns of a person’s fingerprint to validate their identity. The proliferation of electronic devices with fingerprint scanners has made this one of the most widely adopted biometric methods.

Facial anatomy

With the prevalence of laptops, tablets, and mobile devices equipped with cameras, facial recognition has become a popular biometric authentication method.

Facial recognition systems analyze the unique characteristics and geometry of a person’s face to confirm their identity. Each human face has around 80 nodal points, including the distance between the eyes, the width of the nose, and the length of the jawline. 

Scanners convert these nodal points into a faceprint or an encrypted digital model. Advanced systems also perform “liveness detection” to prevent spoofing attempts using static images.

Iris/retina scans

Iris and retina scans involve the analysis of unique eye features for authentication. Retina scans analyze the distinctive pattern of blood vessels around the eye, while iris scans analyze the colored rings found within the iris. Iris scanners collect nearly 240 biometric identification features for precise authentication.

Eye scans are accurate but tricky to implement because they need infrared light sources, compatible cameras, and low-light conditions.

Voice authentication

Voice recognition technologies analyze the unique tone, pitch, and accent of a person’s voice to validate their identity. Physical traits such as the shape of the nose and the length of the vocal tract determine a person’s voice, making it a viable authentication factor. 

Like with facial recognition, voice authentication systems can use liveness tests for additional security to prevent spoofing attempts. 

Multimodal authentication

Similar to multi-factor authentication (MFA), multimodal biometric authentication is an advanced security approach that combines two or more biometric identifiers to verify a user's identity.

By simultaneously utilizing various biometric traits, such as fingerprints, facial recognition, voiceprints, or iris scans, this method aims to overcome the limitations and vulnerabilities associated with single-modal biometric systems.

Multimodal biometrics is a compelling authentication method for organizations requiring heightened security. It significantly enhances security and reduces the risk of unauthorized access, making it more challenging for malicious actors to breach security systems.

Emerging biometric authentication methods

In addition to established biometric technologies, several emerging methods are gaining ground:

• Gait recognition. Gait recognition systems use a person's manner of walking to validate their identity. Factors such as step length, stride, foot and hip angles, and gait cadence are considered in this form of authentication.

• Vein recognition. Vein recognition systems analyze the unique pattern of blood vessels in a person’s hand or finger to validate their identity. When implemented correctly, vein recognition offers exceptional accuracy. Notably, Amazon Go stores employ a form of vein recognition in their palm scanners for shoppers.

Biometric authentication use cases

Here are some examples of how different biometric methods are used nowadays.

Why biometric authentication is growing

Let’s shed some light on some key factors driving the rising prominence of biometric authentication approaches.

Biometric scanners are in everyone’s hands – literally

This widespread accessibility to biometric scanners is reshaping how individuals interact with their digital world, making authentication more seamless and secure than ever before.

The global popularity of smartphones with built-in fingerprint and facial recognition have brought biometric authentication into the mainstream. As major tech companies like Apple, Google, and Samsung continue to refine and expand their biometric offerings, adopting these technologies is expected to skyrocket in the coming years.

Password challenges

The prevalence of passwords in online activities has introduced user friction and security challenges. Users often struggle to create and remember strong, unique passwords for multiple accounts. Forgotten passwords lead to user drop-off and complex reset procedures. Reusing passwords across accounts elevates the risk of credential stuffing and account takeover.

In contrast, biometric authentication provides a more secure and convenient alternative. Fingerprint or face recognition scans are quicker than typing passwords and eliminate the need for users to remember complex passwords, reducing user churn and drop-offs.

The passkeys revolution

Biometrics-enabled devices ignited biometric authentication, while WebAuthn and passkeys are accelerating its adoption. The Web Authentication API empowers web applications to employ device-based biometrics for secure, convenient, and passwordless user registration and authentication. Passkeys are built on WebAuthn and enable cross-device authentication using biometrics. 

With increasing support from popular browsers and operating systems, passkeys are poised to power authentication for several applications soon.

Looking for a way to test your WebAuthn flows? Check out Virtual WebAuthn, a set of Go tools that help developers test WebAuthn flows without needing a browser or an actual authenticator.

Privacy protections

Privacy concerns surrounding biometric authentication have led to the enactment of various privacy acts and regulations. 

During the 2023 legislative session, multiple states (including Arizona, Hawaii, Maryland, Massachusetts, and others) have introduced approximately 15 biometric privacy law proposals. These proposals seek to establish new regulations governing the collection and use of biometric information, encompassing data like retina scans, fingerprints, and voiceprints. 

Modeled after Illinois's Biometric Information Privacy Act (BIPA), these bills include provisions for private actions and damages, potentially increasing compliance requirements and liabilities for companies handling biometric data. Given the fragmented regulatory landscape, businesses should ensure their data practices align with these evolving laws, especially if they deal with residents of states considering BIPA-like legislation.

FIDO Certified biometric authentication solutions prioritize privacy even further. They ensure that biometric information is never stored on servers; instead, it is encrypted and locally stored on the user's device.

Also read: Passwordless Authentication 101

Pros and cons of biometric authentication

Biometric authentication is the key to enhanced security and user convenience, but like any technology, it comes with its own set of advantages and considerations.

Advantages of biometric auth

• Enhanced security. Biometric authentication, rooted in "who users are," is significantly more resistant to theft and misuse than passwords, PIN codes, and other knowledge-based authentication methods. Using biometric authentication based on WebAuthn also ensures that user secrets remain secure, reducing the potential attack surface.

• Improved user experience. Utilizing a fingerprint scanner or glancing at a camera for biometric authentication is considerably faster than manually entering credentials. Additionally, biometric authentication doesn’t require users to create and memorize passwords, reducing churn and drop-off rates.

• Widespread adoption. Biometrics are built into everyday electronic devices and used by a wide range of applications. Multiple surveys have found that users prefer using biometrics over passwords, with 68% citing convenience as the primary reason for their preference. 

Considerations of biometric auth

• Failed authentication in edge cases. Despite the immutability of an individual's biometrics, certain conditions can result in failed authentication. For instance, fingerprint sensors may not function well with wet or dirty hands, or voice recognition may fail if the user has a sore throat.

• Potential training data bias. Training data for biometric authentication systems has historically been biased toward white males, leading to identification inaccuracies in women, people of color, and other underrepresented groups. Tech companies are actively addressing this issue and striving to make improvements.

• Inability to reset biometrics. Unlike passwords, which can be changed if compromised, biometric data cannot be altered if stolen. Consequently, it is vital to store user biometric data locally rather than on centralized servers.

No / low code biometric auth with Descope

Biometric authentication is shaping a more secure and convenient digital world. With biometric scanners now common in our devices, technologies like fingerprint recognition and facial analysis are revolutionizing how we access information. The global biometric market is booming, highlighting trust in this approach.

Descope helps developers easily add biometrics to their apps with no-code workflows. This includes capabilities such as:

• Using biometrics for strong MFA.

• Adding passkey authentication, including autofill and backup capabilities.

• Promoting biometrics as a second factor after user registration.

Create a Free Forever account to start using Descope today. Have questions about our platform? Book time with our auth experts.