Tag Archives: fingerprint

What Are Fingerprint Minutiae?

(Imagen 4)

(Part of the biometric product marketing expert series)

Because many of the subscribers and followers of my Substack page aren’t fingerprint experts (although a few are), my posts on Substack tend to be more introductory. So I wrote this for Substack, but also decided to share it on the Bredemarket blog at some point.

So let’s define what fingerprint minutiae are. 

To do this, look at the tip of one of the fingers on your hand…but not too closely. (Or just Level 2, not Level 3.)

If you look sort of closely at your fingertip, you see one commonality between (most) fingers and Ruffles: both have ridges. For purposes of this exercise, take a close look at where the ridges go.

  • In some cases, the ridges just stop and go no further.
  • In other cases, a single ridge splits into two or more ridges. Or if you want to follow a different perspective, two or more ridges combine into a single ridge. But that perspective screws up the discussion later.
  • Ridges do other things which I will ignore for now.

The important things is that you can identify the specific point at which a ridge ending occurs. And you can identify the specific point of a bifurcation, where a ridge splits into two ridges. (If a ridge splits into three, that’s a trifurcation.)

Those ridge ending and bifurcation points? Those are the minutiae.

Human fingerprint examiners can identify these minutiae points.

So can the algorithms on an automated fingerprint identification system (AFIS) or an automated biometric identification system (ABIS).

And if two fingers have minutiae in the same locations, and don’t have minutiae in one finger that are not present on the other finger…then they’re the same finger. (I’m simplifying here, since the quality of the prints and the way the skin bends affect the ability to find minutiae.)

Which means that if the police find a fingerprint on a stolen car that doesn’t belong to the owner…

…and the minutiae on your finger match the minutiae on the print from the car…

…you’d better have a good lawyer.

Oh, and one more thing: you also have ridges, ridge endings, and bifurcations on your palms and toes. So don’t try to steal a car while barefoot.

Four Time-bound Geolocations = Identity?

(Imagen 4)

(Part of the biometric product marketing expert series)

Some don’t believe that geolocation is a valid factor of identity/verification/authentication.

Some do.

If you ignore what Yves-Alexandre de Montjoye et al said about the validity of 12 fingerprint minutiae points in their 2013 study (cited in phys.org), their conclusions about cell phone locations deserve consideration.

“By analyzing 15 months of cell phone mobility data from 1.5 million people, researchers have found that only four spatio-temporal points (an individual’s approximate whereabouts at the approximate time when they’re using their cell phone) are all that’s needed to uniquely identify 95% of the individuals.”

Why?

“[T]he researchers’ data shows that just four spatio-temporal points are needed to uniquely identify the mobility trace of an individual. In other words, it’s not likely that someone else will be in the same locations as you are at four different times of day.”

And once you perform multi-factor authentication by combining geolocation with another factor, such as an address or a social media post, privacy disappears.

And now a word from our sponsor.

Fictional “The Amazing Computer” TV Show From 1975

Imagen 4 tried to generate this picture, but even with my second prompt attempt (below) it didn’t understand what an FBI tenprint card was.

I couldn’t get Walter Cronkite in there either, so I settled for a generic newsman.

My prompt:

Please generate a realistic picture of a 1975 television show called The Amazing Computer. The picture shows an FBI fingerprint card with ten rolled inked prints and four slap prints sitting on a gargantuan flatbed scanner. A newsman is talking about the technology.

For the real (not fictional) story, read what Dorothy Bullard wrote.

Identity Verification for Nevada Sex Workers

(Part of the biometric product marketing expert series)

There is a lot of discussion about identity verification for people working in certain jobs: police officers, teachers, financial professionals, and the like.

With one exception.

One job that isn’t frequently discussed in the identity verification world is that of a sex worker. Primarily because sex workers usually don’t undergo identity verification for employment, but identity checks for criminal proceedings.

With a few exceptions. 

In portions of Nevada sex work is legal. But it is heavily regulated. So there are laws in places like Carlin, Nevada that govern prostitute registration and work cards. Among other things:

  • Applicants are fingerprinted and are also required to submit a recent photo.
  • Applicants must provide their birth name and all subsequent “names or aliases used.”
  • Three years of residence addresses and employment information.
  • The applicant criminal record “except minor traffic violations.”
  • “A waiver of release of medical information,” since the nature of the work involves the possibility of transmission of communicable diseases. And you thought being a nuclear power plant worker was dangerous!

Presumably the fingerprints are searched against law enforcement databases, just like the fingerprints of school teachers and the other newer professions.

Why?

“The chief of police shall investigate, through all available means, the accuracy of all information supplied by the prostitute on the registration form.”

Included in the investigation:

  • Controlled substance criminal convictions.
  • Felony convictions.
  • Embezzlement, theft, or shoplifting convictions.
  • Age verification; you have to be 21.

As you can see, the identity verification requirements for sex workers are adapted to meet the needs of that particular position.

But…it takes two to tango.

Brothel clients need to be at least 18 years old.

But I don’t know if Nevada requires client age verification, or if age estimation is acceptable.

From https://www.instagram.com/share/_mMj2BVRh.

Contactless Changes

(Wildebeest hoofprint contactless capture via Imagen 3)

(Part of the biometric product marketing expert series)

I can’t tell you why, but I’m performing some intensive research on contactless fingerprint capture. This is a topic I addressed here in 2021 and again in 2022.

As part of my research, I ran across a more recent white paper issued by the Institute for Defense and Government Advancement.

The white paper is entitled “Contactless: The Next Step in Fingerprinting Technology.”

Before I downloaded the white paper, I saw the author: Kaustubh Deshpande.

Kaustubh Deshpande? know that guy. We worked together at MorphoTrak and IDEMIA for a decade.

In fact, the IDGA page lists Deshpande’s IDEMIA affiliation.

Although by the time the paper was published on the IDGA website on February 10, 2025, Deshpande had already left IDEMIA to accept a position at HID.

Everything must change.

Forgot About Faulds

Nowadays, everybody wanna say that they got big TED talks

But nothin’ comes out when they press their fingers

Just a bunch of gibberish 

And CSIs act like they forgot about Faulds

And my N. P. E. Bredemarket Instagram metabot forgot too.

But at least he didn’t cite Gabe Guo.

And I don’t have a rap career.

Forgot About Faulds.

Frictionless Friction Ridges and Other Biometric Modalities

I wanted to write a list of the biometric modalities for which I provide experience.

So I started my usual list from memory: fingerprint, face, iris, voice, and DNA.

Then I stopped myself.

My experience with skin goes way beyond fingerprints, since I’ve spent over two decades working with palm prints.

(Can you say “Cambridgeshire method”? I knew you could. It was a 1990s method to use the 10 standard rolled fingerprint boxes to input palm prints into an automated fingerprint identification system. Because Cambridgeshire had a bias to action and didn’t want to wait for the standards folks to figure out how to enter palm prints. But I digress.)

So instead of saying fingerprints, I thought about saying friction ridges.

But there are two problems with this.

First, many people don’t know what “friction ridges” are. They’re the ridges that form on a person’s fingers, palms, toes, and feet, all of which can conceivably identify individuals.

But there’s a second problem. The word “friction” has two meanings: the one mentioned above, and a meaning that describes how biometric data is captured.

No, there is not a friction method to capture faces.
From https://www.youtube.com/watch?v=4XhWFHKWCSE.

No, there is not a friction method to capture faces. Squishing 

  • If you have to do something to provide your biometric data, such as press your fingers against a platen, that’s friction.
  • If you don’t have to do anything other than wave your fingers, hold your fingers in the air, or show your face as you stand near or walk by a camera, that’s frictionless.

More and more people capture friction ridges with frictionless methods. I did this years ago using MorphoWAVE at MorphoTrak facilities, and I did it today at Whole Foods Market.

So I could list my biometric modalities as friction ridge (fingerprint and palm print via both friction and frictionless capture methods), face, iris, voice, and DNA.

But I won’t.

Anyway, if you need content, proposal, or analysis assistance with any of these modalities, Bredemarket can help you. Book a meeting at https://bredemarket.com/cpa/

MFB = Multi Factor Biasification?

There’s a paper from Itiel Dror that I need to read. Its title is “Biased and Biasing: The Hidden Bias Cascade and Bias Snowball Effects.”

Here is a portion of the abstract:

“Cognitive bias…impacts each and every aspect of the justice and legal systems, from the initial engagement of police officers attending the crime scene, through the forensic examination, and all the way to the final outcome of the jurors’ verdict and the judges’ sentencing. It impacts not only the subjective elements in the justice and legal systems but also the more objective scientific elements, such as forensic fingerprinting and DNA….[S]uch errors in the final outcome rarely occur because they require that the shortcomings in each element be coordinated and aligned with the other elements. However, in the justice and legal systems, the different elements are not independent; they are coordinated and mutually support and bias each other, creating and enabling hidden bias cascade and bias snowball effects.”