How Fingerprint Biometric Authentication Works

Robert MacDonald

Biometrics have come a long way, but the humble fingerprint scan still provides excellent security for enterprise systems.

What is Fingerprint Authentication? It uses the unique characteristics of the human fingerprint as a form of strong authentication.

What Is Biometric Authentication?

Biometric authentication uses factors of inherence (physical features or behavioral traits) as a form of identity verification.

In the earliest days of computing, it was considered sufficient to use a single factor for authenticating users accessing local machine resources. Even with the rise of the early Internet, most authentication was done through a simple username/password combo.

The combination of advanced security threats, mobile devices, and scanning devices has led the security world (both consumer and business to adopt widespread multi-factor authentication (MFA), specifically using biometric authentication.

Biometrics inherently comes with a few distinct advantages, namely:

  • Uniqueness: Physical features, especially those tied to human fingerprints and facial features, are unique compared to a large population. As such, using these patterns as an ID is incredibly effective in asserting identity.
  • Liveness: Most biometrics shortcut a weakness of text-only authentication–namely, the user doesn’t have to be present. Instead, a fingerprint or facial scene requires (outside of sophisticated spoofing tactics) that the user be physically present at the point of authentication.
  • Simplicity: No one has to remember biometrics. Unlike passwords, which, in truth, many people shortcut by reusing phrases or using weak phrases, biometrics are readily available and require no engagement, just scan and authenticate.

Some of the most common forms of biometric authentication used today include:

How Does Fingerprint Authentication Work?

Fingerprint authentication, also called fingerprint biometrics, uses the unique characteristics of the human fingerprint.

The human fingerprint is composed of ridges and lines that represent a pattern wholly unique to the person when taken as a whole. Fingerprint uniqueness has been a cornerstone of law enforcement and media regarding law enforcement, and even in 2022, forensic science has not come across two identical fingerprints, even across identical twins.

Because of this, fingerprints are a great category of features for biometric identification. Furthermore, because modern fingerprint scanning technology has become both sophisticated and widely available, it’s relatively easy to use, find, and integrate into a security system.

Four basic steps are involved in the fingerprint authentication process:


For users to actually benefit from fingerprint authentication, they must onboard. At this stage, the user will typically interact with the device to provide fingerprint information through a fingerprint scanner. The scanner will often require the user to repeatedly scan their finger to get an accurate picture of the patterns contained therein.

On the backend, this fingerprint information will be encoded into a biometric schema or a data representation that can be used as a comparison point during authentication sessions in the future. This template is stored in a database for future reference.


Users who want to access a system via a fingerprint authentication-enabled device place their finger upon the fingerprint scanner.

Currently, there are four types of scanners:

  • Optical: Optical scanners, as the name suggests, use visible light to take the image of a fingerprint placed on a glass plate. It then creates an inverted image that represents the fingerprint. These scanners are fairly accurate and inexpensive, but it’s critical that the surface remains clean or there could be reduced performance.
  • Capacitive: Capacitive scanners use small electrical charges to “charge” the fingerprint and use the capacitive potential of human skin against air gaps between ridges to map the print accurately. A little more sensitive than their optical counterparts, these are much more resistant to fraud due to the inability of hackers to use prosthetics.
  • Thermal: Thermal scanners use heat much the same way as capacitive scanners use electricity. With heat differentials between parts of a fingerprint, the scanner can construct a schema for the fingerprint with solid accuracy. However, it requires the device to generate heat, which may be a no-go for most devices.
  • Ultrasonic: Rather than use light, ultrasonic scanners use sound pulses as a sort of “sonar” reading the surface of the fingerprint. This is a slower authentication method than light-based solutions, but it is highly accurate.

Comparison and Authentication

Once the fingerprint is scanned, it is transformed into a biometric schema, encrypted, and sent to the authentication service, where it is compared against the user’s original schema. If there is a match, then authentication is given.

It’s important to note that some flexibility is provided in the comparison process. That is, the authentication mechanism will usually compare and approve fingerprint schemas within a failure rate. This is because changes to the scanner (scratches, dirt) or to the finger (dirt, sweat, cuts) could change the fingerprint enough to throw a false positive, even if the print is mostly visible.

What Are the Benefits and Drawbacks of Fingerprint Authentication?

Biometrics are the cornerstone for authentication and MFA, but there are many differences between the different types of biometrics. Accordingly, Fingerprints come with significant benefits and drawbacks, depending on what the enterprise needs.

What Are the Benefits of Fingerprint Authentication?

  • Added Security: No biometric is 100% secure, and fingerprints are no different. They are, however, pretty darn secure, and for everyday use, fingerprint scans are more than sufficient for protecting devices.

If your organization needs more security or something more in line with certain compliance standards, then other forms of biometrics might be a better choice.

  • Simple to Deploy: Devices with fingerprint scanners aren’t hard to find or deploy. While fingerprint authentication is a bit more expensive in terms of initial investment, the overall cost compared to other biometrics is pretty low without sacrificing much.
  • Cost-Effective: Alongside the ease of deployment, the low cost is also a great bonus. Your business won’t break the bank by buying laptops or phones with fingerprint scanners.

What Are the Drawbacks of Fingerprint Authentication?

  • Fingerprint Damage: Fingerprints are unique but also subject to damage and degradation over time. Cuts, burns, or simple aging can transform a fingerprint into an unrecognizable pattern over time. Unfortunately, this can present a problem because once the print is damaged, there’s no reusing it. Most of us come with multiple prints to use.
  • Stolen Patterns and Schemas: Fingerprint scans are typically theft-resistant, but only partially. Hackers can steal schemas from security databases to use as a way to fool authentication systems.

Additionally, while incredibly difficult, it’s also possible for creative hackers to craft synthetic fingerprints to use at the point of scanning. The use of thermal or capacitive scanners mitigates this latter approach.

Leverage Strong Biometrics for Passwordless Security with 1Kosmos

Fingerprint authentication is but one form of biometrics common to mobile devices and workstations. 1Kosmos combines strong biometrics with distributed, blockchain-supported identity management, streamlined user onboarding, and compliant identity assurance measures to offer enterprise businesses a way to control authentication simply and securely.

With 1Kosmos, you get the following benefits:

  • Identity-Based Authentication: We push biometrics and authentication into a new “who you are” paradigm. BlockID uses biometrics to identify individuals, not devices, through credential triangulation and identity verification.
  • Identity Proofing: BlockID verifies identity anywhere, anytime and on any device with over 99% accuracy.
  • Privacy by Design: Embedding privacy into the design of our ecosystem is a core principle of 1Kosmos. We protect personally identifiable information in a distributed identity architecture, and the encrypted data is only accessible by the user.
  • Private and Permissioned Blockchain: 1Kosmos protects personally identifiable information in a private and permissioned blockchain, encrypts digital identities, and is only accessible by the user. The distributed properties ensure no databases to breach or honeypots for hackers to target.
  • Interoperability: BlockID can readily integrate with existing infrastructure through its 50+ out-of-the-box integrations or via API/SDK.

If you’re ready to learn about BlockID and how it can help you remain compliant and secure, learn more about what it takes to Go Beyond Passwordless Solutions. Make sure you sign up for the 1Kosmos email newsletter for updates on products and events.

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Meet the Author

Robert MacDonald

Vice President of Product Marketing

Robert is the Vice President of Product Marketing at 1Kosmos. He is a highly influential senior global marketer with more than 15 years of marketing experience in B2B and B2C software in the biometric authentication space. Prior to 1Kosmos, Rob managed product strategy and vision for the Identity and Access Management portfolio at Micro Focus, leading a team of product marketers to drive sales and support the channel. Earlier in his career he set the foundation for content planning, sales enablement and GTM activities for ForgeRock. He has also held senior marketing positions at Entrust, Dell, Quest and Corel Corporation.