The 3 Core Types of Biometrics

May 21, 2019 • Shannon Flynn


Biometrics involves taking measurements from humans’ bodies, behaviors or both. Then, people can use them for authentication purposes, or to help identify individuals in crowds. Here are the three types of biometrics and some examples of methods that fall under each category.

1. Physiological Biometrics

People frequently refer to physiological biometrics as static because they don’t change over time.

This is the category that’s arguably most familiar to people who watch spy or science-fiction movies. That’s because physiological biometrics are often used to grant or deny access to restricted areas.

For example, iris scanners move across the colored part of a person’s eye before evaluating whether to let them in or keep them out. Retina scanners assess the blood vessels in a person’s retina.

There are also fingerprint scanners, and people have gotten more familiar with those thanks to high-tech smartphones that have built-in readers. It’s common for people who check in for work at their jobsites to press their fingers onto these devices, and some airports require passengers to insert their fingers into similar readers when getting their passports scanned.

Hand geometry is another physiological biometric. Setting up that kind of scanner requires measuring several dimensions of a person’s hand, then storing those measurements in a file for later retrieval and comparison.

It’s one of the oldest forms of biometrics and was patented in 1985. However, it’is not as precise as a method that verifies a person’s eye characteristics because the hand doesn’t have any wholly unique data points.

Similar to hand geometry is a biometric technique that checks the anatomical features of a person’s ear. An Android app utilizing that method claims an individual only needs to press their phone to their ear to engage in it.

However, other, more minute forms can measure aspects of the hand, such as vein biometrics. They check a person’s finger. An investigation also applied electric pulses to a person’s body and measured the response.

2. Behavioral Biometrics

In contrast to physiological biometrics that measure unchangeable things about people, behavioral biometrics aim to detect patterns in human behavior.

Although physiological biometrics usually require hardware to work, behavioral biometrics typically just need software. That means this variety is often less expensive to implement.

Signature recognition is one type of behavioral biometrics. It looks at the aspects of the signature, such as the slope and contouring of the letters. Alternatively, handwriting biometrics is an offshoot of this option. It involves people scribbling more things than just their names.

Behavioral biometrics can verify a person’s identity throughout their online experiences. For example, they might measure a person’s typing speed, the pressure they put on the keyboard or even the position of their fingers.

3. Physiological/Behavioral Biometrics

Physiological/behavioral biometrics have components taken from both the categories mentioned above.

Voice and speech recognition is among the well-known types of biometrics in this combined category. It measures things such as frequency, cadence, tone and inflection. Smart speakers that differentiate between voices use these biometrics.

People should bear in mind, though, that the line between physiological and behavioral biometrics in this example is often a blurry one. Some individuals consider voice biometrics as purely behavioral.

Some kinds of gait recognition fall into this section, too. It monitors how a person walks, but some techniques also look at body silhouettes, ear shapes and other characteristics spanning beyond movement.

Researchers also blended behavioral and physiological biometrics by measuring the precise ways people use touch-screen devices. They required people to unlock the gadgets by using their fingers to operate a virtual lock screen wheel.

The scientists found that being right- or left-handed was a behavioral characteristic that partially affected how people worked that feature of the phone.

In other cases, researchers combined a person’s fingerprints along with a metric such as typing speed. People who use those options often assert that these physiological/behavioral measurements are exceptionally complicated to forge.

In contrast, a person could potentially find it easier to make a spoof of a behavioral analysis alone, like a signature.

An Area of Continual Investigation

Although these categories describe the three primary types of biometrics, it’s crucial for people to remember that work is ongoing to figure out other ways to identify people through their physical characteristics or habits.

One of the more unusual examples of scientists determining what’s possible in the biometrics field concerns identifying people by how they smell.

The push to evaluate new methods is not surprising. Security is an ever-present issue in today’s society, especially with the prevalence of data breaches and network hacks.

In many cases, asking someone for a password is no longer sufficient. Biometrics could fill the gap.