(Part of the biometric product marketing expert series)
Now that I’m plunging back into the fingerprint world, I’m thinking about all the different types of fingerprint readers.
- The optical fingerprint and palm print readers are still around.
- And the capacitive fingerprint readers still, um, persist.
- And of course you have the contactless fingerprint readers such as MorphoWave, one that I know about.
- And then you have the multispectral fingerprint readers.
What is multispectral?
Bayometric offers a web page that covers some of these fingerprint reader types, and points out the drawbacks of some of the readers they discuss.
Latent prints are usually produced by sweat, skin debris or other sebaceous excretions that cover up the palmar surface of the fingertips. If a latent print is on the glass platen of the optical sensor and light is directed on it, this print can fool the optical scanner….
Capacitive sensors can be spoofed by using gelatin based soft artificial fingers.
From https://www.bayometric.com/fingerprint-reader-technology-comparison/
There is another weakness of these types of readers. Some professions damage and wear away a person’s fingerprint ridges. Examples of professions whose practitioners exhibit worn ridges include construction workers and biometric content marketing experts (who, at least in the old days, handled a lot of paper).
The solution is to design a fingerprint reader that not only examines the surface of the finger, but goes deeper.
The specialty of multispectral sensors is that it can capture the features of the tissue that lie below the skin surface as well as the usual features on the finger surface. The features under the skin surface are able to provide a second representation of the pattern on the fingerprint surface.
From https://www.bayometric.com/fingerprint-reader-technology-comparison/
Multispectral sensors are nothing new. When I worked for Motorola, Motorola Ventures had invested in a company called Lumidigm that produced multispectral fingerprint sensors; they were much more expensive than your typical optical or capacitive sensor, but were much more effective in capturing true fingerprints to the subdermal level.
Lumidigm was eventually acquired in 2014: not by Motorola (who sold off its biometric assets such as Printrak and Symbol), but by HID Global. This company continues to produce Lumidigm-branded multispectral fingerprint sensors to this day.
But let’s take a look at the other word I bandied about.
What is liveness?
“Gelatin based soft artificial fingers” aren’t the only way to fool a biometric sensor, whether you’re talking about a fingerprint sensor or some other sensor such as a face sensor.
Regardless of the biometric modality, the intent is the same; instead of capturing a true biometric from a person, the biometric sensor is fooled into capturing a fake biometric: an artificial finger, a face with a mask on it, or a face on a video screen (rather than a face of a live person).
This tomfoolery is called a “presentation attack” (becuase you’re attacking security with a fake presentation).
But the standards folks have developed ISO/IEC 30107-3:2023, Information technology — Biometric presentation attack detection — Part 3: Testing and reporting.
And an organization called iBeta is one of the testing facilities authorized to test in accordance with the standard and to determine whether a biometric reader can detect the “liveness” of a biometric sample.
(Friends, I’m not going to get into passive liveness and active liveness. That’s best saved for another day.)
[UPDATE 4/24/2024: I FINALLY ADDRESSED THE DIFFERENCE BETWEEN ACTIVE AND PASSIVE LIVENESS HERE.]
Multispectral liveness
While multispectral fingerprint readers aren’t the only fingerprint readers, or the only biometric readers, that iBeta has tested for liveness, the HID Global Lumidigm readers conform to Level 2 (the higher level) of iBeta testing.
There’s a confirmation letter and everything.
This letter was issued in 2021. For some odd reason, HID Global decided to publicize this in 2023.
Oh well. It’s good to occasionally remind people of stuff.
Bredemarket 