Riding the wind of rebirth

"The advantages of this technology are that it is relatively mature, adaptable to temperature-dependent fingerprint processing, inexpensive equipment, and can achieve a relatively high resolution of 500 DPI. However, the disadvantage is that to achieve such a high resolution, the light path must travel a sufficient distance, so the size requirement is relatively large. In addition, excessively dry or oily fingers will also degrade the performance of optical fingerprint products."

“These are not the key points.” Zhou Zhi shook his head: “Your application scenario is door locks, so how to prevent counterfeiting is the key. The biggest drawback of optical technology is liveness detection. In other words, using an image or a silicone fingerprint mold for optical recognition may achieve the same effect as using a real fingerprint.”

This is depicted in many movies. For example, a master thief obtains fingerprints from a wealthy person's wine glass and then uses those fingerprints to create a fingerprint mold to unlock the wealthy person's security mechanisms.

"Have you been watching too many movies?" Xu Anxin asked.

"Just tell me, is it even possible?"

“Then it’s only semiconductor silicon technology,” Xu Anxin said, “that is, CMOS technology.”

CMOS technology is a relatively new technology, having been developed for about ten years and put into application for about five years. It is used as a pressure-sensitive device in many situations, such as in Qin Haifeng's Marine Power Research Institute, where it is widely used to collect pressure changes of cavitary fluid under different states and paths. Therefore, Zhou Zhi is also familiar with it.

It is actually a sensor designed based on the semiconductor silicon capacitance effect. When used in fingerprint technology, the sensor acts as one plate of a capacitor, and the finger is the other plate. By utilizing the capacitance difference between the ridges and valleys of the fingerprint line and the smooth silicon sensor, a grayscale image can be formed.

"Can this technology perform liveness detection?"

"It doesn't say it can perform liveness detection, but it can achieve better image quality than optical technology on smaller surfaces, and its resolution is improving very quickly following Moore's Law. However, its disadvantages are that it is susceptible to interference and its reliability is relatively worse than that of optical technology, but there is a lot of room for improvement."

“That’s still not appropriate.” Zhou Zhi shook his head again: “How about we give up on fingerprints?”

"Huh? You don't support us making fingerprint locks?" Xu Anxin's eyebrows shot up.

"No, what I mean is that what you're doing right now is meaningless. This kind of fingerprint recognition technology is somewhat boring. I'm asking you, what's the difference between this kind of recognition technology and facial recognition?"

"Facial recognition?"

"That's right. Anyway, it's all about reading biometrics, and it doesn't have any penetration capabilities. What's the difference between me using a camera to read fingerprints and me using a camera to take a picture of my face? Don't forget, facial recognition is a technology we mastered before we even evolved into humans. It's practically the oldest biometric reading technology. It's even more mature than fingerprint technology."

"The features are more obvious, the reading is more convenient, and the user experience is better. Isn't it better than fingerprint recognition?"

"Moreover, even if optical technology is used for collection, people can freely set the optical path, unlike fingerprint collection devices which are subject to constraints."

"It seems...that makes sense, huh?" Xu Anxin discovered that when using optical technology to match fingerprints and faces, two different biometric features, facial recognition seemed to have the advantage.

"What if I also use photos?" Li Laosan started arguing when he saw that his wife couldn't win the argument with Zhou Zhi.

“Could we add infrared ranging?” Zhou Zhi tapped his chin with his finger. “I know that facial recognition can be enhanced with an infrared standard network. It can test the facial feature value of each network focal point. This feature value is also included in the distance difference of the surrounding feature values, which would constitute stereo detection.” “Then I can bring a statue.”

"This can be supplemented with facial motion recognition, such as blinking, eye movement, pupil changes in light, micro-expressions, etc., requiring customers to cooperate with actions such as turning their heads or bowing their heads for liveness verification."

"Then I'll wear a mask."

"Then let's add an infrared temperature detector. The temperature distribution on a masked face is definitely different from that on a real face."

"Honey, wait a little longer, I'm going to knock this elbow down..."

"What are you doing!" Xu Anxin slapped Li Laosan: "The ideas that Zhouzi came up with are all good ones that inspire our thinking, why are you still being stubborn!"

"Hahaha..." Zhou Zhi laughed too: "That's right, why should I, a liberal arts student, answer your difficult questions? Wouldn't it be better for you to find an expert to solve them yourselves?"

I decided to share what I knew about biometric technologies from later generations with them. After all, I was the head of the IT department in a large company back then, and I was also in charge of bidding for the access control and computer room access control systems. I knew a bit about the technology: "Besides fingerprints and facial features, the biometric features I know include body shape recognition, pupil recognition, eye capillary recognition, fingertip capillary recognition, and so on."

"These can all be done in conjunction with liveness detection technology. For example, the pupil can adjust its direction, contract and dilate at any time, and there are blood pressure changes and blood flow phenomena in capillaries at any time. If these technologies are relatively mature, I think using them is more reliable than fingerprint recognition."

"However, overall, fingerprint technology is still the most widely used and cheapest biometric identification technology. But you should determine the degree of its application, which mainly refers to the recognition rate or the fault tolerance rate."

"The accuracy of identification varies in different application scenarios. For example, for a small unit of about ten people, the accuracy can be set very high because it is almost impossible for the same features to appear."

“But for an application scenario involving tens of thousands or even hundreds of thousands of people, the recognition accuracy must be improved to a very high threshold in order to solve the problems that Third Brother just raised.” After saying that, he smiled at Li Laosan and said, “You didn’t think of that, actually twins are quite difficult to identify.”

Li Laosan slapped his forehead: "Damn! That's right! How come I didn't think of that?!"

Zhou Zhi continued to explain to Xu Anxin some of the detours he had taken when purchasing identification equipment: "If you want to read fingerprints, it is best to use penetrating devices, such as infrared devices or ultrasonic devices, because fingerprints on the skin surface are easily affected by excessive moisture, oil, dryness, peeling, calluses, and abrasion. Therefore, reading information from the epidermis often results in the inability to identify and compare them. So it is best to use penetrating devices for both the collection and comparison devices to directly read the grain and ridge patterns of the dermis layer under the epidermis."

"I originally thought it was a pretty simple thing. Just change your edge acquisition and comparison algorithm to fingerprint feature acquisition and comparison. But after you explained it like this, it seems like things have become complicated again."

“Complexity means being ahead of its time and irreplaceable.” Zhou Zhi smiled and said, “I would suggest that Jinan entrust AXA Fund to look for technology patents and research papers in the areas mentioned above, both domestically and internationally. If reliable technologies have emerged, buy them as your own technology reserves before the market realizes their value. This will also allow you to conduct further research and development on your own, in conjunction with the R&D center.”

"If we're not going to do it, we won't do it at all. But if we're going to do it, we'll do it world-class!" (End of Chapter)