knee, modality

Not the bee’s knees

Biometrics Using Internal Body Parts: Knobbly Knees in Competition With Fingerprints (Science Daily)

Forget digital fingerprints, iris recognition and voice identification, the next big thing in biometrics could be your knobbly knees. Just as a fingerprints and other body parts are unique to us as individuals and so can be used to prove who we are, so too are our kneecaps. Computer scientist Lior Shamir of Lawrence Technological University in Southfield, Michigan, has now demonstrated how a knee scan could be used to single us out.

Every once in a while a version of the above paragraph finds itself in the news…

Forget digital fingerprints, iris recognition and voice identification, the next big thing in biometrics could be your ______________.

Bone structure or electric conductivity?

I suspect that any definable aspect of the human anatomy could be used as a biometric identifier. In instances where teeth are all that is known about an individual, they are used for high confidence identification.

A good biometric modality must be: unique, durable, and easily measurable. If any of these are missing, widespread use for ID management isn’t in the cards. If something is unique and durable but isn’t easily measurable, it can still be useful but it isn’t going to become ubiquitous in automated (or semi-automated) technology. Teeth and DNA fit this model. Teeth have been used to determine the identity of dead bodies with a high degree of certainty for a long time, but we aren’t going to be biting any sensors to get into our computers any time soon — or ever. Likewise with DNA.

There is also the challenge of proving that a modality is in fact unique, durable and easily measurable which requires a whole lot of experimental data and (especially regarding uniqueness) a healthy dose of statistical analysis. I’m no statistician, and from what I understand, the statistical rules for proving biometric uniqueness aren’t fully developed yet anyway, so let’s just leave things in layman’s terms and say that if you’re wanting to invent a new biometric modality and someone asks you how big a data set of samples of the relevant body part you need, your best answer is “how many can you get me?” 

In order to ascertain uniqueness you need samples from as many different people as you can get. For durability you need biometric samples for the same person taken over a period of time and multiplied by a lot of people. 

Ease of measure is more experiential and will be discovered during the experimentation process. The scientists charged with collecting the samples from real people will quickly get a feel for the likelihood that people would adapt to a given ID protocol.

For two common biometric modalities, face and fingerprint, huge data repositories have existed since well before there was any such thing as a biometric algorithm. Jails (among others) had been collecting this information for a hundred years and the nature of the jail business means you’ll get several samples from the same subject often enough to test durability, too, over their criminal life. For face, other records such as school year books exist and were readily available to researchers who sought to test the uniqueness and durability of the human face.

Iris, voice, and the vascular biometrics of the hand (palm, finger) have apparently joined face and fingerprint biometrics in achieving wide-scale commercial viability despite the lack of historic data repositories. They either occupy prime real estate on the head and the end of the arm (Iris, vein), or they are the only biometric that can be used over a ubiquitous infrastructure that simply isn’t going anywhere (voice/phone).  

In order to displace finger/hand and face/eye biometrics in wide scale deployments, novel biometric modalities will have to out-compete them on two levels: in the lab and in the market meaning they will have to offer out-sized advantages in order to justify the R&D outlay required to “catch up”. This is highly unlikely to happen with any novel modality.

In order to thrive as high value-added tools in highly specialized deployments, however, a novel modality just needs to help solve a high value problem (teeth, DNA).

Any biometric modality can be useful, especially if it’s the only one available. But that’s not likely ever to be the case for many of these novel modalities, knees included.

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