Next Biometrics, The Active Thermal Principle, And Your Future Smartphone

September 18, 2015 | Seth Colander from Tom's Hardware

Next Biometrics competes with a handful of other companies that make fingerprint sensors for mobile devices (think Apple’s Touch ID or Qualcomm’s Sense ID), but it doesn’t see itself as an also-ran — Next believes itself to be the (future) 900-pound gorilla, because of its superior (and cheaper) technology and research.

The Oslo, Norway-based company is headed by a subdued but clearly passionate CEO in Tore Etholm-Idsøe. When you speak with him about the company and its technology, his voice is steady, but he leans in, and he doesn’t parlay in corporate-speak. He sounds like a product guy who believes in the Thing he’s showing you.

So it was in my time with him in a recent meeting in New York, where Etholm-Idsøe, flanked by his silent CFO and a PR specialist, explained why Next Biometrics is poised to offer what they believe to be the best biometric sensor for the burgeoning market — with all due respect, they would say, better than Apple, better than Qualcomm.

The Active Thermal Principle

One of the most fascinating developments in biometrics that we at Tom’s Hardwarehave observed in recent months is how so many companies are taking completely different approaches.

Qualcomm’s ultrasonic Sense ID uses sound waves to scan the details of your finger, whether or not there’s moisture present. Apple’s solution uses capacitive technology that relies on a weak electrical signal. Upstart Vkansee uses an optical scanner, a thin film Matrix Pinhole Imaging Sensor (MAPIS) that goes beneath a device’s glass and can read even wet fingers. And so on.

Next Biometric’s technology is based on the “Active Thermal Principle,” in which the warmth from your finger transfers to the sensor, and the sensor uses that unique imprint to determine who is the user. “When you place your finger on our sensor, there are 45,000 pixels. When I place the finger here, it wakes up, and it adds heat into each pixel. That heat will transfer very efficiently into the finger where there is contact. So in the ridges of the print you will have an efficient and fast heat flow,” said Etholm-Idsø.

He continued, “In the valleys of your print, where there is air, you will not [have the same heat flow]. And this is a major difference between contact and not contact, and it allowed us to map the print — and to do so very fast. We read these 45,000 pixels in 0.35 seconds.”

In other words, your own body heat generates a pulse, which is measured by each of those tens of thousands of pixels according to the ridges in your fingerprint.

“The key to what makes this interesting is this: Each pixel here consists of a small resistor and a diode only. So the pixel design is extremely simple. The capacity guys are much more complex, so they need transistors and capacitances, etc., and to get the right resolution, the pixel needs to be very small,” he said.

This simple design allows Next Biometrics to keep manufacturing costs quite low, because it can use low temperature poly-silicon display fabs and use standard production processes. “We manufacture sheets of glass, not using expensive silicon, and using a less complex production process. So the sheets may be almost the size of that screen [points to a smartphone prototype with a 4-inch display]. We fit 840 sensors into each sheet. And if you take a competitive sensor, if you compare them at the module level (not at the sensor level), [ours] is 70-80 percent cheaper. So it’s a major shift.”

Etholm-Idsø further explained why he believes Next Biometric’s approach is superior to others. “People are trying to look for smaller features, sweat pores and scars, but the problem with those is that they are not constant over time,” he said. He has a point. If you authenticate your fingerprint, what happens if you have a cut on the surface of your finger — even a small one? That could throw off the read and give you a failed authentication attempt, because the sensor effectively has less data to work with.

He further stated that pores, for example, are not static. They open and close, and thus they are larger or smaller depending on the weather, or the temperature in a room. Humidity can affect pores, too.

This is also why Next contends that a high-res sensor may not be helpful at all; even if the higher-res solution can see something as tiny as sweat pores, those pores may be closed or open, and that can seriously affect the accuracy of the sensor’s read.

Even when he contrasts the Active Thermal Principle against capacitive sensor solutions, Etholm-Idsøe will readily admit that his competitors’ technologies have their merits. “Apple has the strongest portfolio there. And it’s a strong principle,” he allowed. “It has some weaknesses in terms of wet fingers — so if you take a can of Coke out of the fridge and try to use the [iPhone’s Touch ID], you will easily get a false detection because it doesn’t like water too much. But otherwise, it’s fairly comparable in performance — if the size is comparable.”

But that “if” is also part of Next Biometric’s winning formula.

Size Matters

In the tech industry, we’re accustomed to the idea that smaller is better. But in the biometrics market, that may not be the case, according to research that Next Biometrics commissioned.

“The dominant determinator of the sensor system quality is size. It’s not the resolution, it’s not the sensing principle, it’s not algorithm (those are all more or less alike) — it’s the sensor size,” said Etholm-Idsøe.

Dubbed the “Madrid Report,” Next Biometrics asked researchers at the Universidad Carlos III de Madrid to examine the relationship between the size of a sensor and its performance. Conducted by Professor Raul Sanchez-Reillo, the study pitted three different sensors against one another to see which was the most accurate.

If you’re skeptical of any study that was commissioned by a company whose results show that the commissioning entity’s product is superior, you’re not alone. We pressed Etholm-Idsøe on the study’s validity, and he noted that although Next Biometrics certainly funded the research (“Someone has to cover the costs,” he correctly noted), the actual study was performed independently, using the research methods determined by Professor Sanchez-Reillo and his team.

To learn more details of the study, how it was set up and conducted, and a deeper breakdown of the results, you can also read both the summary of the Madrid Report and the full study on Next Biometric’s website.

The results of the Madrid Report indicate that, indeed, size appears to affect false rejection rates (FRR). In high-security settings (such as payments and corporate access), Next Biometric’s full-size (12 x 17 mm) NB-1010-U sensor performed at a “robust” level (although it wasn’t quite as accurate as the THE TCS-1.) In low-security settings (such as unlocking your smartphone), all three sensors performed superbly when their full size was used.

When the researchers reduced the surface area of the sensors, the accuracy dropped across the board.

The logic here, which is presented in the study results, is simple: A larger sensor collects a large amount of data. A medium-sized sensor collects a moderate amount of data. A small sensor collects a small amount of data.

The point that Next Biometrics hopes to make by citing this research is that its large sensor performs reasonably well compared to more expensive large sensors in both high security and low security scenarios, and also that when OEMs implement the sensors, they need to leave the full surface area exposed in order to enable the sensors’ full accuracy.

Sensors On The Back

The insinuation, then, is that therein lies a design problem: You don’t want this (relatively) huge sensor taking up valuable real estate on the front of your phone, or wherever. Next Biometrics has a solution to that problem, which is to place the sensor on the back of a device like a smartphone.

The Next Biometrics team brought a prototype phone with them to show what that might look like. You can see on the back about how much of the phone is occupied by the sensor (as well as the size of the sensor assembly itself). In the prototype, it looks a bit ugly; but if you look at a recent implementation in the Blu Pure XL, you can see that a sensor on the back of a phone can be elegant enough. (Note that the sensor on the Blu Pure XL is from a competitor, not Next Biometrics. The point of this illustration is that a rear-embedded sensor can look nice.)

Next Biometrics recently announced its own ultra-slim, bezel-less sensor for just this application too, though.

In practical use, this design makes sense. I found that when I held the prototype phone, my finger naturally landed on the sensor, particularly when I held it as if I was making a phone call. (Yes, kids, some people still talk on the phone.) The front of the phone, then, can also remain uncluttered by the sensor.

Angling For The Payment And Security Industries

Although it is true that Next Biometrics has sensor solutions for devices like smartphones, tablets and laptops, there are other significantly lucrative uses for accurate biometrics, as well.

The payments industry, and applications such as authenticating employees before they can enter the building (or a secret lab, you can use your imagination), are ripe for the picking.

There are multiple technologies brewing in the payments market, including those from Apple and Google, but Next Biometrics is taking a platform-agnostic approach to the lot of them. Next Biometrics, Etholm-Idsøe explained, simply makes the module. “Obviously this is going to be a race between the traditional payment industry [players] — between the banks, and MasterCard and Visa and the smart card players on one side. You have the mobile network operators who want a cut of this. You have Silicon Valley players wanting to cut in. You have players like Alibaba who want a share,” he said, adding, “This is a big thing. And we want to be friends with all of them [laughs].”

He showed me a prototype of a keyfob that would use PayPass from MasterCard. Etholm-Idsøe noted that such keyfobs already exist, but without security. “If I take your PayPass keyfob, I can run around and do whatever. Now, [with this Next-enabled keyfob], integrating a sensor into it, we can build a device cheap enough for that application.” He said that all a user would have to do to use a secure, cheap keyfob like this one is to enroll and register your fingerprint on the device. “There is no change being done to the PayPass infrastructure,” he said. But then in terms of security, “Your key fob will not work, will not start communicating with the outside world, before the correct finger is detected.”

If you happen to lose it, he noted, the keyfob would be useless in the (literal) hands of anyone else. Your financial data is thus secure. Further, because it’s an inexpensive device with an inexpensive sensor, you could replace a lost or stolen keyfob for around $15.

Windows Hello

One of the impressive new security features that Microsoft baked into Windows 10 is an authentication feature called “Hello.” Simply put, the technology allows a user to log into a device using fingerprint, facial or iris authentication. We’ve seen the “sexy” version of this — a person logging into a PC with just his face — from Microsoft numerous times on stage at events, but logging in to your PC with the swipe of a finger is just as compelling in real-world instances.

Next is in the mix for the many, many designs that OEMs are building with Windows 10 on board. “We’re qualified,” said Etholm-Idsøe. “We’re in the system, as part of Windows [10] update, and so any sensor built by us will work immediately with Windows.” He noted that there aren’t actually many players in that space, and so Next has a good chunk of Microsoft’s (and OEMs’) attention.

Next’s sensors are also qualified for Microsoft hardware specifically, although the company wouldn’t deign to comment on whether or not it is involved with any new Microsoft designs. (We’re just guessing here, but we wouldn’t be shocked if the next Surface Pro or flagship Lumia handset shipped with a fingerprint sensor, and if so, Next is likely in the mix for getting those deals.)

Looking To Dominate

Above all, what Next Biometrics has going for it at present is its ability to mass produce its designs — something Etholm-Idsøe said that most of the company’s competitors aren’t able to do, regardless of how innovative their solutions may be.

He showed me six sensor designs — another, as we mentioned above, has just been announced — which the company is ready to roll out in bulk. Its fab and manufacturing partners are able to pump out as many as half a million modules per month, and it could scale that upwards within 3-6 months if need be.

Next just recently announced that it received an order worth $100,000 from an OEM to produce a standalone authentication device called “the Oyster” (pictured), which is slated to launch sometime this year, as well as a large, multi-year order from (another undisclosed) company for some 100,000 sensors per year.

Next Biometrics believes in its technology and is ready to produce. Look for the company’s modules in everything from smartphones and tablets, to wearables, to payment devices, and more starting soon.