Can Touch ID make a comeback?

     If it weren't for masks, we wouldn't be so disgusted with Apple's Face ID.

　　Even though the neural engine of the iPhone's A-series chip has an 'autonomous learning' mechanism that can allow Face ID to recognize you behind a mask through multiple training sessions, this is actually not reliable.

　　I remember that in April this year, my iPhone suddenly recognized me wearing a mask, which made me feel like a child who had grown up. But the good times didn’t last long. As I stayed at home for a few weeks and wore a mask less frequently, it immediately forgot about me wearing a mask. It was very ruthless.

　　The iPhone's Face ID keeps learning. It can remember you wearing a mask, but it can also quickly forget it. This is not a long-term solution.

　　Recently, in the iOS 14.5 beta, support for unlocking iPhone with Apple Watch has been added, which can be regarded as alleviating the problem of Face ID being difficult to use. However, for those users who do not have an Apple Watch, they will not be able to enjoy this "ecological advantage". Unlocking iPhone with Apple Watch is not the "final solution", but a "delaying tactic".

　　At the same time, there are endless rumors that the new iPhone will adopt "under-screen fingerprint", which seems to be a foregone conclusion. And the new iPhone will retain under-screen fingerprint and Face ID, complementing each other to facilitate user selection, or to deal with different situations (wearing a mask).

　　Is Touch ID really coming back?

　　Face ID has made two changes to masks

　　Faced with the impact of masks, Apple's response strategy was relatively conservative. It was not until the end of April that the unlocking solution was optimized in the iOS 13.5 Beta 3 firmware.

　　Let's review first. Before iOS 13.5, when the iPhone saw a 'mask', Face ID could not recognize your face and would confirm again and again, and then pop up the password interface after 1 second. Of course, you can also click the 'face icon' on the Face ID interface to skip the recognition process and enter the password directly. Either way, it does not simplify the recognition process, and even makes unlocking more complicated.

　　iOS 13.5 Beta 3 has added recognition for masks. After recognizing the mask, it directly "gives up" facial recognition and pops up the password interface directly, which optimizes the unlocking process.

　　The latest iOS 14.5 Beta 1 goes a step further on this basis. Similar to MacBook, you can use Apple Watch to unlock it, playing with the "ecosystem". I will not go into the specific "unlocking experience" and "security" here. You can move to the article "Finally, you can unlock the iPhone with a mask, but we found these problems after the experience" to view it.

　　It took nearly a year from the initial wearing of masks to the introduction of a more reasonable solution. The current Apple Watch unlocking solution is still a "temporary solution but not a fundamental solution". From the actual situation, it is obvious that Touch ID is more user-friendly and convenient, and the call for the return of Touch ID is getting stronger.

　　Faced with masks, Face ID is indeed easily defeated, and the advantages of Touch ID are highlighted. Some of my friends have switched to iPhone SE2 equipped with Touch ID or even switched to Android because of the unlocking method.

　　In the Android camp, under-screen fingerprint recognition is almost standard, and 3D structured light biometric recognition similar to Face ID is almost non-existent. It is a different path from Apple, and naturally more adaptable to "masks" and brings a better experience. So, why did Apple choose Face ID instead of under-screen fingerprint recognition?

　　Why is Apple betting on Face ID? Is under-screen fingerprint not popular?

　　Face ID was released together with iPhone X. iPhone X laid the foundation for the design style of subsequent notch screens, while Face ID led Apple's new generation of biometric technology.

　　Now we already know that Face ID is based on 3D structured light, and uses radar to scan and record the face. It is not affected by glasses, beards, hats, etc., and will "grow" with your face over time, making full use of the computing power of the neural engine of the A-series bionic chip.

　　When Face ID was first launched, its security was questioned. Apple stated at the press conference and on its official website that Face ID is 20 times more secure than Touch ID, with the former being one in a million and the latter being one in fifty thousand. In other words, the upgrade from Touch ID to Face ID also upgrades the security level.

　　In addition, under normal conditions, the user experience of Face ID is actually higher than that of Touch ID. The biggest advantage of Face ID is that it is invisible. You don’t need to press the button, just scan it with your eyes to complete the recognition and unlocking. At the same time, Face ID is not affected by the environment, and can provide a consistent experience regardless of day or night, cold or hot, while Touch ID is relatively limited to certain conditions.

　　In fact, long before the release of iPhone X, Apple already had a patent for under-screen fingerprint recognition, so there were many reports in the supply chain that the new iPhone would have an under-screen version of Touch ID. Later, we all knew what Apple chose.

　　I chose Face ID because it has a better experience and security, and because the under-screen fingerprint technology is not yet mature. I vaguely remember that when the under-screen fingerprint was first introduced, the recognition and unlocking process was a bit "clumsy".

　　In addition, the under-screen fingerprint, or more accurately the 'optical under-screen fingerprint' is not as secure as the traditional capacitive fingerprint, and this should be the 'last straw' for Apple to switch to Face ID.

　　How to put Touch ID under the screen?

　　In the past, Android manufacturers would emphasize how fast and accurate the under-screen fingerprint recognition of their new phones was at press conferences, and would also say that "it is equipped with the xxth generation of under-screen fingerprint recognition." Now, manufacturers rarely mention under-screen fingerprint recognition at press conferences. On the one hand, under-screen fingerprint recognition technology is gradually maturing, and on the other hand, it is no longer new and has become a standard feature.

　　If it weren't for the existence of 'masks' in 2020, we might not have the desire to return to Touch ID, and Face ID would not bring any inconvenience to our lives.

　　At present, under-screen fingerprint technology is gradually maturing, and the still unclear "global epidemic" seems to have begun to make Apple rethink how to make trade-offs between security and practicality. Using Apple Watch to unlock the iPhone is a compromise made at the expense of security for convenience.

　　It seems that while ensuring security and portability, Touch ID combined with Face ID would be the optimal solution.

　　At present, there are about three solutions for under-screen fingerprint, each with its own advantages and disadvantages.

　　Optical fingerprint recognition

　　The standard solution for under-screen fingerprint recognition in the Android camp. The principle is simply to take a photo of the fingerprint and then compare and identify it.

　　The module is small in size, thin in thickness, fast in recognition, and has a high unlocking success rate. However, it can only be used on OLED screens, and the finger cleanliness level must be high. In addition, the optical under-screen fingerprint does not currently support "live detection", and its security and anti-counterfeiting performance are slightly poor.

　　Ultrasonic fingerprint recognition

　　Qualcomm dominates and is commonly seen in Samsung Galaxy flagship phones. The latest Galaxy S21 series is equipped with Qualcomm's second-generation 3D ultrasonic fingerprint recognition. The principle is similar to the sonar system, which uses the texture of the finger to identify the difference in the reflection and penetration of sound waves.

　　Compared with optical under-screen fingerprint recognition, ultrasonic fingerprint solutions have higher penetration and certain anti-stain capabilities. The most important thing is that they support liveness detection, which has a higher security level. In addition, the screen does not need to be illuminated during the recognition process, which will not affect the screen life. Cost control, mass production capabilities, and technical maturity are all somewhat different from optical fingerprints.

　　Capacitive fingerprint recognition

　　Capacitive fingerprint recognition is a relatively ideal solution, supporting liveness detection without losing recognition speed. In addition, in principle, it can also support full-screen unlimited "blind operation".

　　At present, if Apple wants to have an under-screen fingerprint, it will most likely use these three solutions. However, if it wants to achieve the security of the previous physical Touch ID, it will most likely choose one of the two solutions: 3D ultrasonic and under-screen capacitive.

　　Can Touch ID return?

　　When Touch ID was first introduced, it completely overturned the industry's "fingerprint recognition", and it turned out that fingerprint recognition could be so invisible. And when Face ID was introduced, it re-established the standard of "facial recognition", and it turned out that the security level of facial recognition could be so high.

　　Apple usually does not try out a new technology first, but waits until the time is right, combines software and hardware, and gradually optimizes to make it "invisible". According to this idea, the experience of the iPhone's under-screen fingerprint should be different from the existing solutions, and full-screen recognition is more in line with Apple's tone.

　　From the information revealed so far, it all points to the optical under-screen fingerprint, but it does not reach the security level that Apple needs. The optical under-screen fingerprint is likely to be a "compromise solution" similar to the unlocking of Apple Watch, which can only unlock the phone but cannot make payments. Naturally, it should not be called Touch ID, but is more like the concept of Touch Locker.