5 Popular Types of Biometric Authentication: Pros and Cons

5 Popular Types of Biometric Authentication: Pros and Cons

September 9, 2021

By in Blog

Today's biometric authentication methods are divided into different types, but all of them have similar goals. What’s more, the core of the way they function is also alike: they measure and analyze the unique characteristics inherent to a specific person in order to confirm that person’s identity. 

Because of that, physical documents are gradually becoming a thing of the past and are being replaced by biometric identification. It can also be said that modern technology has come a long way, allowing people to unlock mobile devices with fingerprints or transfer money with the help of voice commands.

Even though biometric authentication methods are beneficial, each of them has its pros and cons. In this article, we want to take a closer look at the advantages and disadvantages of different types of biometric authentication technologies to help you decide which one is the right choice for your company. 

Let’s start with establishing what we mean by biometrics.

What Is Biometrics?

Biometrics is the analysis of unique biological and physiological characteristics with the aim of confirming a person's identity. The five most common types of biometric identifiers are: fingerprints, facial, voice, iris, and palm or finger vein patterns.

As an example, banks need your biometric data in order to provide their various services remotely. If you want to open an account or take out a loan then you used to have to go to a branch, whereas now you can access many services over the phone.

The Most Widely Used Types of Biometric Systems

There are two types of biometric systems: physical biometrics and behavioral biometrics. Let’s see how they differ from each other.

Physical Biometrics

With the help of special devices (scanners, sensors, and other readers), a person's biometric data is stored in a database. The system saves this information, such as a fingerprint, and converts it into digital data. Then, when the finger is placed back on the scanner, the system compares the new data with what is stored in its database. Finally, the system will either confirm the person’s identity and grant them access if there is a match or decline the request if not.

Modern smartphone cameras and video recorders can easily recognize faces with the help of built-in sensors powered by neural networks. In this sense, the image becomes a person’s identifier. This technology can be used not only to unlock phones, but also for more complex tasks such as confirming purchases or accessing financial services.

Behavioral Biometrics

Behavioral biometrics is a recognition system that identifies a person based on dynamic or behavioral characteristics. These characteristics may include handwriting and signature dynamics, voice and speech rhythms, gesture recognition, electronic device usage characteristics through typing speed, the way a person holds a smartphone or tablet, and even the way they walk. This type is also known as passive biometrics, as it doesn’t require a user's active participation to proceed with the authentication process.

These dynamic authentication methods are based on the characteristics of a person's behavior. They evaluate a person's unique behavior and subconscious movements in the process of reproducing any action. 

Voice recognition is a technology that combines both physical and behavioral biometrics as it analyzes dynamic and static characteristics of human voice at the same time.

Five Types of Biometric Identification with Their Pros and Cons

Let's take a look at the current five most popular types of biometric identification and analyze their advantages and disadvantages.

Fingerprint Scanning

Fingerprint recognition is a type of physical biometrics. For this authentication method, a fingerprint scanner is used to authenticate data. 

Even with the variety of biometric systems, we can simply divide them into three types that work in three different ways: converting a fingerprint into a digital code with an optical sensor, saving conversion using a linear thermal sensor, and converting a fingerprint with a capacitive authentication sensor. Despite this variety, the only difference for the end-user is which manipulations are to be performed with the scanner, i.e., applying their finger (optical and capacitive) or guiding it through a sensor (thermal).

Advantages of Fingerprint Scanning:

  • Fingerprints are unique identifiers specific to the individual.
  • Most people are familiar with this authentication method.
  • No need to remember complex passwords.
  • Fingerprint scanners are relatively cheap and can even be bought on Amazon.

Disadvantages of Fingerprint Scanning:

  • Injuries, temporary or permanent, can interfere with scans.
  • It is a technology that can be bypassed with methods that copy and replicate fingerprints. It’s hard to copy one’s fingerprint, but it’s not impossible.
  • It can be bypassed by using someone else’s finger while they are asleep or unconscious.

Voice Recognition

Voice is a feature as inherent to each person as their fingerprints or face. The fact that so many companies worldwide use phones for communication offers an excellent opportunity for the use of this biometric authentication method. Moreover, voice recognition is very convenient for users and requires minimum effort on their side.

Voice biometric authentication technology is widely used in several areas directly related to processing users' voices, such as in call centers. Adoption of this biometric technology allows for speeding up of the service, making the work of agents easier, and helping them become more efficient. This technology can have many different use cases such as security systems, credit card verification, forensic analysis, and teleconferencing, etc. In larger projects, especially when the need to protect confidential information is great, voice identification can be applied with another authentication method such as fingerprint scanning.

Advantages of Voice Recognition:

  • No need to remember and then use a password while being authenticated.
  • Voice is a natural way of communication and interaction between people.
  • It saves time for both users and agents, especially when using passive voice biometrics.
  • The voice is a unique feature that is extremely hard to falsify.
  • It’s a widely used method that is familiar to users.

Disadvantages of Voice Recognition:

  • Users may not understand how their data is stored and have privacy-related concerns.
  • Noisy places may prevent successful authentication.
  • Severe respiratory illness may decrease the success rate of authentication.

Iris Recognition

Iris scanning technology was first proposed in 1936 by ophthalmologist Frank Bursch (source). In the early 1990s, John Dufman of Iridian Technologies patented an algorithm for detecting differences in the iris. At the moment, this biometric authentication method is one of the most accurate and is performed with the help of dedicated iris scanners.

This is how the technology works: First, the pupil is located, followed by detecting the iris and eyelids. Next, unnecessary parts such as eyelids and eyelashes are excluded to leave only the iris part, which is divided into blocks and converted into numerical values representing the image. Finally, matching with previously collected data is performed using the same methods to verify identity.

Advantages of Iris Recognition:

  • Iris is an internal organ that is well protected against damage by a highly transparent and sensitive membrane. Thus, it’s unlikely for minor injuries to influence scanning devices.
  • The iris is an invariant organ with a high level of randomness between individuals.
  • No need to memorize complicated passwords.

Disadvantages of Iris Recognition:

  • This technology is relatively new and still requires improvements.
  • It is a method that requires a short distance between the device and the user's eye.
  • In low light conditions, the chances of iris recognition are really poor.

Facial Recognition

Facial recognition is the automatic localization of a human face in an image or video. If necessary, facial recognition technology can be used to confirm a person's identity based on the available data - an image of someone’s face stored in a database as mathematical code. Interest in this technology is high because this method can be applied in videoconferencing. 

Advantages of Facial Recognition:

  • Requires little interaction with the device.
  • It is widely used and people are used to this type of technology.
  • Highly effective when combined with other biometric methods.
  • No need to memorize complex passwords.

Disadvantages of Facial Recognition:

  • Lighting changes can affect the system's performance.
  • Facial expressions may change the system's perception of the face.
  • The use of facial accessories may make it difficult to recognize the user.
  • It may cause embarrassment for some users to have to look at their phone often to unlock it.

Handwriting Recognition

Dynamic signature verification can be applied in areas requiring workflow automation, such as banking or judicial systems. Signature recognition is based on pattern recognition algorithms or mathematical methods of curve analysis, since a set of points can represent a signature. Therefore, these systems often use time series decomposition or curve approximation.

Advantages of Handwriting Recognition:

  • Signatures were used to confirm identities for centuries. Thus, this technology evokes trust.
  • The technology doesn’t require advanced devices to work (touchscreen devices are common these days).
  • It’s intuitive and natural and doesn't require much explanation.

Disadvantages of Handwriting Recognition:

  • Many people have inconsistent signatures.
  • Injuries like broken arms or fingers may make it impossible to use this technology.
  • This method is suitable only for low-level security operations.


As you can see, there are many biometric authentication methods available on the market. Each of them has its advantages and disadvantages, but you can be sure of one thing - any method listed in this article is safer than a typical password. That’s why we encourage you to analyze each technology described in this article and decide which one to implement in your company. The future is passwordless.

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