Iris Recognition, Apple, and Worldcoin

(Part of the biometric product marketing expert series)

Iris recognition continues to make the news. Let’s review what iris recognition is and its benefits (and drawbacks), why Apple made the news last month, and why Worldcoin is making the news this month.

What is iris recognition?

There are a number of biometric modalities that can identify individuals by “who they are” (one of the five factors of authentication). A few examples include fingerprints, faces, voices, and DNA. All of these modalities purport to uniquely (or nearly uniquely) identify an individual.

One other way to identify individuals is via the irises in their eyes. I’m not a doctor, but presumably the Cleveland Clinic employs medical professionals who are qualified to define what the iris is.

The iris is the colored part of your eye. Muscles in your iris control your pupil — the small black opening that lets light into your eye.

From https://my.clevelandclinic.org/health/body/22502-iris
From Cleveland Clinic. (Link)

And here’s what else the Cleveland Clinic says about irises.

The color of your iris is like your fingerprint. It’s unique to you, and nobody else in the world has the exact same colored eye.

From https://my.clevelandclinic.org/health/body/22502-iris

John Daugman and irises

But why use irises rather than, say, fingerprints and faces? The best person to answer this is John Daugman. (At this point several of you are intoning, “John Daugman.” With reason. He’s the inventor of iris recognition.)

Here’s an excerpt from John Daugman’s 2004 paper on iris recognition:

(I)ris patterns become interesting as an alternative approach to reliable visual recognition of persons when imaging can be done at distances of less than a meter, and especially when there is a need to search very large databases without incurring any false matches despite a huge number of possibilities. Although small (11 mm) and sometimes problematic to image, the iris has the great mathematical advantage that its pattern variability among different persons is enormous.

Daugman, John, “How Iris Recognition Works.” IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 14, NO. 1, JANUARY 2004. Quoted from page 21. (PDF)

Or in non-scientific speak, one benefit of iris recognition is that you know it is accurate, even when submitting a pair of irises in a one-to-many search against a huge database. How huge? We’ll discuss later.

Brandon Mayfield and fingerprints

Remember that Daugman’s paper was released roughly two months before Brandon Mayfield was misidentified in a fingerprint comparison. (Everyone now intone “Brandon Mayfield.”)

If you want to know the details of that episode, the Department of Justice Office of the Inspector General issued a 330 page report (PDF) on it. If you don’t have time to read 330 pages, here’s Al Jazeera’s shorter version of Brandon Mayfield’s story.

While some of the issues associated with Mayfield’s misidentification had nothing to do with forensic science (Al Jazeera spends some time discussing bias, and Itiel Dror also looked at bias post-Mayfield), this still shows that fingerprints are remarkably similar and that it takes care to properly identify people.

Police agencies, witnesses, and faces

And of course there are recent examples of facial misidentifications (both by police agencies and witnesses), again not necessarily forensic science related, and again showing the similarity of faces from two different people.

Iris “data richness” and independent testing

Why are irises more accurate than fingerprints and faces? Here’s what one vendor, Iris ID, claims about irises vs. other modalities:

At the root of iris recognition’s accuracy is the data-richness of the iris itself. The IrisAccess system captures over 240 degrees of freedom or unique characteristics in formulating its algorithmic template. Fingerprints, facial recognition and hand geometry have far less detailed input in template construction.

Iris ID, “How It Compares.” (Link)

Enough about claims. What about real results? The IREX 10 test, independently administered by the U.S. National Institute of Standards and Technology, measures the identification (one-to-many) accuracy of submitted algorithms. At the time I am writing this, the ten most accurate algorithms provide false negative identification rates (FNIR) between 0.0022 ± 0.0004 and 0.0037 ± 0.0005 when two eyes are used. (Single eye accuracy is lower.) By the time you see this, the top ten algorithms may have changed, because the vendors are always improving.

IREX10 two-eye accuracy, top ten algorithms as of July 28, 2023. (Link)

While the IREX10 one-to-many tests are conducted against databases of less than a million records, it is estimated that iris one-to-many accuracy remains high even with databases of a billion people—something we will return to later in this post.

Iris drawbacks

OK, so if irises are so accurate, why aren’t we dumping our fingerprint readers and face readers and just using irises?

In short, because of the high friction in capturing irises. You can use high-resolution cameras to capture fingerprints and faces from far away, but as of now iris capture usually requires you to get very close to the capture device.

Iris image capture circa 2020 from the U.S. Federal Bureau of Investigation. (Link)

Which I guess is better than the old days when you had to put your eye right up against the capture device, but it’s still not as friendly (or intrusive) as face capture, which can be achieved as you’re walking down a passageway in an airport or sports stadium.

Irises and Apple Vision Pro

So how are irises being used today? You may or may not have hard last month’s hoopla about the Apple Vision Pro, which uses irises for one-to-one authetication.

I’m not going to spend a ton of time delving into this, because I just discussed Apple Vision Pro in June. In fact, I’m just going to quote from what I already said.

And when all of us heard about Vision Pro, one of the things that Apple shared about it was its verification technique. Not Touch ID or Face ID, but Optic ID. (I like naming consistency.)

From https://bredemarket.com/2023/06/12/vision-pro-not-revolutionary-biometrics-event/
From Apple, https://www.apple.com/105/media/us/apple-vision-pro/2023/7e268c13-eb22-493d-a860-f0637bacb569/anim/drawer-privacy-optic-id/large.mp4

In short, as you wear the headset (which by definition is right on your head, not far away), the headset captures your iris images and uses them to authenticate you.

It’s a one-to-one comparison, not the one-to-many comparison that I discussed earlier in this post, but it is used to uniquely identify an individual.

But iris recognition doesn’t have to be used for identification.

Irises and Worldcoin

“But wait a minute, John,” you’re saying. “If you’re not using irises to determine if a person is who they say they are, then why would anyone use irises?”

Enter Worldcoin, which I mentioned in passing in my early July age estimation post.

Over the past several years, I’ve analyzed a variety of identity firms. Earlier this year I took a look at Worldcoin….Worldcoin’s World ID emphasizes privacy so much that it does not conclusively prove a person’s identity (it only proves a person’s uniqueness)…

From https://bredemarket.com/2023/07/03/age-estimation/

That’s the only thing that I’ve said about Worldcoin, at least publicly. (I looked at Worldcoin privately earlier in 2023, but that report is not publicly accessible and even I don’t have it any more.)

Worldcoin’s July 24 announcement

I guess it’s time for me to revisit Worldcoin, since the company made a super-big splashy announcement on Monday, July 24.

The Worldcoin Foundation today announced that Worldcoin, a project co-founded by Sam Altman, Alex Blania and Max Novendstern, is now live and in a production-grade state. 

The launch includes the release of the World ID SDK and plans to scale Orb operations to 35+ cities across 20+ countries around the world. In tandem, the Foundation’s subsidiary, World Assets Ltd., minted and released the Worldcoin token (WLD) to the millions of eligible people who participated in the beta; WLD is now transactable on the blockchain….

“In the age of AI, the need for proof of personhood is no longer a topic of serious debate; instead, the critical question is whether or not the proof of personhood solutions we have can be  privacy-first, decentralized and maximally inclusive,” said Worldcoin co-founder and Tools for Humanity CEO Alex Blania. “Through its unique technology, Worldcoin aims to provide anyone in the world, regardless of background, geography or income, access to the growing digital and global economy in a privacy preserving and decentralized way.”

From https://worldcoin.org/blog/announcements/worldcoin-project-launches

Worldcoin does NOT positively identify people…but it can still pay you

A very important note: Worldcoin’s purpose is not to determine identity (that a person is who they say they are). Worldcoin’s purpose is to determine uniqueness: namely, that a person (whoever they are) is unique among all the billions of people in the world. Once uniqueness is determined, the person can get money money money with an assurance that the same person won’t get money twice.

OK, so how are you going to determine the uniqueness of a person among all of the billions of people in the world?

Using the Orb to capture irises

As far as Worldcoin is concerned, irises are the best way to determine uniqueness, echoing what others have said.

Iris biometrics outperform other biometric modalities and already achieved false match rates beyond 1.2× ⁣10−141.2×10−14 (one false match in one trillion[9]) two decades ago[10]—even without recent advancements in AI. This is several orders of magnitude more accurate than the current state of the art in face recognition.

From https://worldcoin.org/blog/engineering/humanness-in-the-age-of-ai

So how is Worldcoin going to capture millions, and eventually billions, of iris pairs?

By using the Orb. (You may intone “the Orb” now.)

To complete your Worldcoin registration, you need to find an Orb that will capture your irises and verify your uniqueness.

Now you probably won’t find an Orb at your nearby 7 Eleven; as I write this, there are only a little over 100 listed locations in the entire world where Orbs are deployed. I happen to live within 50 miles of Santa Monica, where an Orb was recently deployed (by appointment only, unavailable on weekends, and you know how I feel about driving on Southern California freeways on a weekday).

But now that you can get crypto for enrolling at an Orb, people are getting more excited about the process, and there will be wider adoption.

Whether this will make a difference in the world or just be a fad remains to be seen.

I Changed My Mind on Age Estimation

(Part of the biometric product marketing expert series)

I’ll admit that I previously thought that age estimation was worthless, but I’ve since changed my mind about the necessity for it. Which is a good thing, because the U.S. National Institute of Standards and Technology (NIST) is about to add age estimation to its Face Recognition Vendor Test suite.

What is age estimation?

Before continuing, I should note that age estimation is not a way to identify people, but a way to classify people. For once, I’m stepping out of my preferred identity environment and looking at a classification question. Not “gender shades,” but “get off my lawn” (or my tricycle).

Designed by Freepik.

Age estimation uses facial features to estimate how old a person is, in the absence of any other information such as a birth certificate. In a Yoti white paper that I’ll discuss in a minute, the Western world has two primary use cases for age estimation:

  1. First, to estimate whether a person is over or under the age of 18 years. In many Western countries, the age of 18 is a significant age that grants many privileges. In my own state of California, you have to be 18 years old to vote, join the military without parental consent, marry (and legally have sex), get a tattoo, play the lottery, enter into binding contracts, sue or be sued, or take on a number of other responsibilities. Therefore, there is a pressing interest to know whether the person at the U.S. Army Recruiting Center, a tattoo parlor, or the lottery window is entitled to use the service.
  2. Second, to estimate whether a person is over or under the age of 13 years. Although age 13 is not as great a milestone as age 18, this is usually the age at which social media companies allow people to open accounts. Thus the social media companies and other companies that cater to teens have a pressing interest to know the teen’s age.

Why was I against age estimation?

Because I felt it was better to know an age, rather than estimate it.

My opinion was obviously influenced by my professional background. When IDEMIA was formed in 2017, I became part of a company that produced government-issued driver’s licenses for the majority of states in the United States. (OK, MorphoTrak was previously contracted to produce driver’s licenses for North Carolina, but…that didn’t last.)

With a driver’s license, you know the age of the person and don’t have to estimate anything.

And estimation is not an exact science. Here’s what Yoti’s March 2023 white paper says about age estimation accuracy:

Our True Positive Rate (TPR) for 13-17 year olds being correctly estimated as under 25 is 99.93% and there is no discernible bias across gender or skin tone. The TPRs for female and male 13-17 year olds are 99.90% and 99.94% respectively. The TPRs for skin tone 1, 2 and 3 are 99.93%, 99.89% and 99.92% respectively. This gives regulators globally a very high level of confidence that children will not be able to access adult content.

Our TPR for 6-11 year olds being correctly estimated as under 13 is 98.35%. The TPRs for female and male 6-11 year olds are 98.00% and 98.71% respectively. The TPRs for skin tone 1, 2 and 3 are 97.88%, 99.24% and 98.18% respectively so there is no material bias in this age group either.

Yoti’s facial age estimation is performed by a ‘neural network’, trained to be able to estimate human age by analysing a person’s face. Our technology is accurate for 6 to 12 year olds, with a mean absolute error (MAE) of 1.3 years, and of 1.4 years for 13 to 17 year olds. These are the two age ranges regulators focus upon to ensure that under 13s and 18s do not have access to age restricted goods and services.

From https://www.yoti.com/wp-content/uploads/Yoti-Age-Estimation-White-Paper-March-2023.pdf

While this is admirable, is it precise enough to comply with government regulations? Mean absolute errors of over a year don’t mean a hill of beans. By the letter of the law, if you are 17 years and 364 days old and you try to vote, you are breaking the law.

Why did I change my mind?

Over the last couple of months I’ve thought about this a bit more and have experienced a Jim Bakker “I was wrong” moment.

I was wrong for two reasons.

Kids don’t have government IDs

Designed by Freepik.

I asked myself some questions.

  • How many 13 year olds do you know that have driver’s licenses? Probably none.
  • How many 13 year olds do you know that have government-issued REAL IDs? Probably very few.
  • How many 13 year olds do you know that have passports? Maybe a few more (especially after 9/11), but not that many.

Even at age 18, there is no guarantee that a person will have a government-issued REAL ID.

So how are 18 year olds, or 13 year olds, supposed to prove that they are old enough for services? Carry their birth certificate around?

You’ll note that Yoti didn’t target a use case for 21 year olds. This is partially because Yoti is a UK firm and therefore may not focus on the strict U.S. laws regarding alcohol, tobacco, and casino gambling. But it’s also because it’s much, much more likely that a 21 year old will have a government-issued ID, eliminating the need for age estimation.

Sometimes.

In some parts of the world, no one has government IDs

Over the past several years, I’ve analyzed a variety of identity firms. Earlier this year I took a look at Worldcoin. While Worldcoin’s World ID emphasizes privacy so much that it does not conclusively prove a person’s identity (it only proves a person’s uniqueness), and makes no attempt to provide the age of the person with the World ID, Worldcoin does have something to say about government issued IDs.

Online services often request proof of ID (usually a passport or driver’s license) to comply with Know your Customer (KYC) regulations. In theory, this could be used to deduplicate individuals globally, but it fails in practice for several reasons.

KYC services are simply not inclusive on a global scale; more than 50% of the global population does not have an ID that can be verified digitally.

From https://worldcoin.org/blog/engineering/humanness-in-the-age-of-ai

But wait. There’s more:

IDs are issued by states and national governments, with no global system for verification or accountability. Many verification services (i.e. KYC providers) rely on data from credit bureaus that is accumulated over time, hence stale, without the means to verify its authenticity with the issuing authority (i.e. governments), as there are often no APIs available. Fake IDs, as well as real data to create them, are easily available on the black market. Additionally, due to their centralized nature, corruption at the level of the issuing and verification organizations cannot be eliminated.

Same source as above.

Now this (in my opinion) doesn’t make the case for Worldcoin, but it certainly casts some doubt on a universal way to document ages.

So we’d better start measuring the accuracy of age estimation.

If only there were an independent organization that could measure age estimation, in the same way that NIST measures the accuracy of fingerprint, face, and iris identification.

You know where this is going.

How will NIST test age estimation?

Yes, NIST is in the process of incorporating an age estimation test in its battery of Face Recognition Vendor Tests.

NIST’S FRVT Age Estimation page explains why.

Facial age verification has recently been mandated in legislation in a number of jurisdictions. These laws are typically intended to protect minors from various harms by verifying that the individual is above a certain age. Less commonly some applications extend benefits to groups below a certain age. Further use-cases seek only to determine actual age. The mechanism for estimating age is usually not specified in legislation. Face analysis using software is one approach, and is attractive when a photograph is available or can be captured.

In 2014, NIST published a NISTIR 7995 on Performance of Automated Age Estimation. The report showed using a database with 6 million images, the most accurate age estimation algorithm have accurately estimated 67% of the age of a person in the images within five years of their actual age, with a mean absolute error (MAE) of 4.3 years. Since then, more research has dedicated to further improve the accuracy in facial age verification.

From https://pages.nist.gov/frvt/html/frvt_age_estimation.html

Note that this was in 2014. As we have seen above, Yoti asserts a dramatically lower error rate in 2023.

NIST is just ramping up the testing right now, but once it moves forward, it will be possible to compare age estimation accuracy of various algorithms, presumably in multiple scenarios.

Well, for those algorithm providers who choose to participate.

Does your firm need to promote its age estimation solution?

Does your company have an age estimation solution that is superior to all others?

Do you need an experienced identity professional to help you spread the word about your solution?

Why not consider Bredemarket? If your identity business needs a written content creator, look no further.