In this blog post, we’ll take a brief look at how Apple’s “Face ID” works, its pros and cons, and some real-world applications.
Smartphones are widely used in various aspects of our lives thanks to their innovative features and excellent usability. As smartphone penetration rates have risen and their scope of use has expanded, more personal information has been stored on them, making smartphones the electronic devices that hold the most personal data. Consequently, smartphone security has always been a critical issue, and it is essential to understand the most basic and essential method of unlocking a device. In this article, we will focus on Apple’s “Face ID,” one of the latest technologies in this field.
“Face ID” is an unlocking feature introduced by Apple on the “iPhone X,” and its greatest advantage is convenience. Simply holding the smartphone and looking at the screen naturally unlocks it, providing a user experience that feels as if the device and the user have become one. Depth-sensing technology was applied to make this possible. The ‘iPhone X’ captures the user’s face using an infrared camera and dot projector sensors located at the top of the front panel; however, this is not simply taking a photo. It projects over 30,000 invisible dots onto the face to map its unique geometric structure for recognition.
The advantage of this mapping is that it is not significantly affected by changes in the user’s appearance. Changes in hairstyle or elements like glasses and hats have almost no effect on the unlocking process. This is because the aforementioned dots and infrared light precisely map the face’s 3D structure. Since 3D images recognize not only color but also distance information at each point, they capture the object in three-dimensional space rather than on a two-dimensional plane. Even before its release, many smartphones—such as the Samsung Galaxy S8, Xiaomi Note 3, and vivo V7+—offered facial recognition features, but these primarily stored faces as 2D images. This method is vulnerable to security breaches, as the device could be unlocked using a user’s selfie; in contrast, the iPhone X recognizes the 3D structure of the face, preventing such issues. Therefore, 3D imaging technology is the key differentiator of Face ID.
However, even the seemingly perfect ‘Face ID’ has its vulnerabilities. First, opinions are divided regarding its reliability; for example, there are concerns that it may struggle to distinguish between identical twins, making it unsuitable for them. Additionally, while one security firm claimed to have successfully bypassed ‘Face ID’ using a fake face created with 3D printing technology, doubts remain about the credibility of their findings since the firm did not disclose the details of the initial setup process. Another drawback is that, unlike the previous ‘Touch ID,’ which allowed users to register up to five fingerprints, ‘Face ID’ only allows for the registration of a single face. While Apple’s intention is understandable, this is a disappointment from the user’s perspective. Furthermore, there are other limitations, such as the system failing to function properly when the face is fully covered, for example, by a mask.
This technology is not limited to simple unlocking. Apple has applied 3D imaging technology to expand its emoji capabilities, resulting in a new form of emoji called “Animoji.” “Animoji” uses 3D imaging technology to recognize changes in the user’s facial expressions in real time and apply them to standard emojis. When the user opens their mouth, the emoji opens its mouth; when the user smiles, the emoji smiles back—making it seem as though the emoji is coming to life.
Based on the above explanation, Apple’s “Face ID” can be considered one of the most advanced unlocking technologies available today. While it meticulously analyzes the user’s face to map its structure as a 3D image, it remains vulnerable to individuals with faces that are extremely similar, such as identical twins. Nevertheless, “Face ID” is innovative and holds great potential for further development. Other manufacturers are already developing similar facial recognition features, and it appears that such capabilities will soon be widely available on Android smartphones as well. Furthermore, building on “Face ID,” developers will create more innovative features like “Animoji,” allowing users to enjoy their smartphones in a more fun and efficient way.
