Various Forms of Biometrics and How They Are Used

From the Lecture series: The Surveillance State: Big Data, Freedom, and You

By Paul Rosenzweig, The George Washington University Law School

From establishing access-control checkpoints to let people into buildings and computer systems to verifying credit and other consumer behavior, a verified biometric identity can be quite useful. And, there are many different forms of biometrics. Let’s explore.

Facial recognition of young woman via polygon mask on face.
Face recognition technology identifies individuals by analyzing certain features on their face like the nose width or the eye sockets or the mouth. (Image: Prostock-studio/Shutterstock)

Fingerprint Biometrics

Biometric fingerprint recognition relies on features found in the impressions made by the distinct ridges on the fingertips. The fingerprint images are scanned, enhanced, and then converted into templates. These templates are saved in a database for future comparisons using optical, silicon, or ultrasound scanners.

In Pakistan, the government requires everyone with a cell phone and SIM card to register with their fingerprints, saying it’s an anti-terror initiative, since untraceable, unregistered SIM cards were proliferating as a means of terrorist communication.

Another area where fingerprint biometrics have been used is for identity and access management in health care. Here, the biometric technology is used to solve the challenge of how hospitals can give access to users and yet maintain security levels that provide confidence and comfort to their patients.

This is a transcript from the video series The Surveillance State: Big Data, Freedom, and You. Watch it now, on Wondrium.

Iris Recognition

Iris recognition technology relies on the distinctly colored ring that surrounds the pupil of the eye. Irises have approximately 266 distinctive characteristics. For iris recognition, typically more than 170 of the distinctive characteristics are used in creating a template.

Irises are thought to remain stable throughout an individual’s life, barring injury. The technology is relatively easy to use and can process a large number of people quickly.

Iris recognition is also only minimally intrusive, in a physical sense. However, colored or bifocal contact lenses might hinder the effectiveness of the system, as can strong eyeglasses. Glare or reflection can also be problematic for the cameras. In addition, oddly enough, people with poor eyesight occasionally have difficulty aligning their eyes correctly with the camera, and people who have glaucoma or cataracts might not be suitable for screening using iris recognition technology.

Biometric Facial Recognition

Face recognition technology identifies individuals by analyzing certain features on their face—the nose width or the eye sockets or the mouth. Typically, facial recognition compares a live person with a stored template, but it’s also been used for comparison between photographs and templates. This technology works for verification, and also for identification.

Indeed, MasterCard is now in the process of trialing a new facial recognition app for your smartphone that’ll let you use your face as a way of verifying your identity and approving your credit card transaction.

In addition, facial recognition is the biometric system that can best be routinely used covertly, since a person’s face can often be captured by video technology. In other words, you may never know if a photo is being taken of you and compared to some database. And it works. DeepFace, the facial recognition technology developed by Facebook, is said to be 97% accurate, making it competitive with human distinguishing capabilities.

Learn more about a history of surveillance in America.

Voice Recognition

Image showing voice recognition concept with smart phone.
Voice recognition is quite non-intrusive. (Image: metamorworks/Shutterstock)

Voice recognition technology identifies people based on vocal differences that are caused either by differences in their physical characteristics—like the shape of the mouth—or from speaking habits—like an accent.

Voice recognition technology can be used for both identification and verification. It’s also fairly inexpensive and very non-intrusive. The biggest disadvantage with the technology is that it can be unreliable. For instance, it doesn’t work well in noisy environments, like airports or border entry points.

Hand-based Biometric System

Another form of physical recognition is a measurement based on the human hand and the width, height, and length of the fingers, distances between the joints, and the shape of knuckles. It’s called hand geometry.

Hand geometry is actually a mature technology primarily used for high-volume time and attendance, and access control. For instance, from donuts to hamburgers, Krispy Kreme and McDonald’s alike rely on hand geometry to record staff time and attendance.

It’s really difficult to spoof someone’s hand shadow without the person’s cooperation. The main advance in the technology over the years has been in cost reduction. Today, a wide variety of places rely on hand geometry for access. The San Francisco Airport uses it for access to the tarmac. The Port of Rotterdam, Scott Air Force Base, and a sorority at the University of Oklahoma all rely on it.

Gait Recognition

Gait analysis using a foot plate in anthropometry.
A drawback of gait analysis is that if you know you’re being watched you can change your gait. (Image: Microgen/Shutterstock)

Gait recognition is an emerging biometric technology. It involves people being identified purely through the analysis of the way they walk. According to the Homeland Security News, scientists in Japan have developed a system measuring how the foot hits and leaves the ground during walking.

They then use 3D image processing and a technique called image extraction to analyze the heel strike, roll-to-forefoot, and push-off by the toes. Some say that accuracy in recognition is up to 90%—with a caveat of course, that if you know you’re being watched you can change your gait.

The idea, however, has attracted interest because it’s non-invasive and doesn’t require the subject’s cooperation. Researchers also envision medical applications for the technology. For example, recognizing changes in walking patterns early on can help identify conditions such as Parkinson’s disease and multiple sclerosis in their earliest stages.

Learn more about the psychological impact on someone being watched.

DNA Biometrics

DNA analysis is, perhaps, the most accurate biometric method of one-to-one identity verification. You’ll likely recall what happened to Bill Clinton after Monica Lewinsky turned over a navy blue dress that she said she had worn during a romantic encounter with the president.

Investigators compared the DNA in a stain on that dress to a blood sample from the president. By conducting the two standard DNA comparisons, the FBI Laboratory concluded that Bill Clinton was the source of the DNA obtained from Monica Lewinsky’s dress.

So, this is how most biomtrics technology works. It is definitely not science fiction, and it is definitely useful.

Common Questions about the Various Forms of Biometrics and How They Are Used

Q: What is fingerprint recognition technology?

Fingerprint recognition is a biometric technology which relies on features found in the impressions made by the distinct ridges on the fingertips.

Q: How does biometric facial recognition work?

Biometric facial recognition technology identifies individuals by analyzing features on their face, such as nose width or the eye sockets or the mouth.

Q: What can be a drawback of gait recognition biometric?

A drawback of gait recognition biometric is that if you know you’re being watched you can change your gait. Thus, reducing its efficacy.

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