What is Touch ID on iPhone?

what is touch id

by Alex Gustman

Updated: June 8, 2021

Apple has installed the Touch ID scanner in four generations of smartphones. This article will let you know what a scanner is, what it is used for, and whether the lack of a sensor in the latest generations of smartphones is so critical.

What is Touch ID?

Touch ID is a fingerprint scanner that Apple has designed for its own products. The scanner has a built-in Home button on the front side of the iPhone 5S, 6/6+, 6S/6S+, iPhone SE, 7/7+ and 8/8+models. And the sensor is also available in the iPad Pro tablets of the first two generations, in the MacBook laptops with TouchBar and in the Air 2019 model.

touch id

Purpose of Touch ID

The scanner is used for authentication when unlocking the smartphone screen. The availability of such a system complicates the hacking of the device in the event of theft or loss of the phone. You do not yet need to use outdated and outdated numeric or alphabetic passwords. And in the iOS 8 version, the manufacturer removed the restriction on third-party use by developers, which allowed the scanner to be used in applications. Touch ID is also used for payment in the Apple Pay payment system.

To use the sensor, you need to first add a fingerprint, which is available when you first set up your phone. In the future, just put your finger on the scanner. Moreover, the reading area recognizes the fingerprint at any angle.

In addition, the scanner is combined with a physical switch of the Home button. The rest of the time, when you do not need to unlock, the key performs the action of returning to the main screen of the desktop.

Touch ID Security

For the user’s security, several layers are used to protect the fingerprint. The print information is stored in a separate memory section on the same chip as the processor. And if it is considered that the memory doesn’t store it in the form of a snapshot, but only a mathematical image, data extraction is a complicated and even impossible procedure. In addition, the Touch ID scanner is tied to a specific “processor”, so replacing the sensor in the smartphone will not do anything. The sensor will simply stop working.

Also, to use Touch ID, you need to set a backup password, which will not allow you to unlock the device after a reboot or if the total time of use has not exceeded 48 hours. The company believes that such an additional measure will help to postpone hacking for intruders.

As for hacking, you can bypass the security system, but under certain circumstances. Attackers need a clear fingerprint of the owner, left, for example, on the glass. Then you will need to transfer the print to the latex to simulate a finger pad. Such a process requires some preparation, the availability of expensive chemicals and specialized equipment, as well as enough time and some experience. And without a high-quality finger print, the idea is not feasible at all.

Switching from Touch ID to Face ID

In iPhone X, XS/XS Max, XR, 11, as well as iPad Pro 2018 tablets, the Touch ID scanner has been replaced with Face ID. In such devices, an additional IR camera is used for unlocking, and the owner’s face is used as biometric material. In this case, you do not need to put your finger to unlock it, just look at the phone screen.

The principle of operation and storage of biometric material is similar to Touch ID. The mathematical image is copied to the hidden area with the processor and is not transmitted anywhere else. Face ID technology remembers the owner’s face, and thanks to neural networks, it learns and distinguishes changes in the face.

Apple refused to use Touch ID because of the superiority and ease of use of Face ID. In addition, the scanner on the front panel takes up valuable space, and the non-availability of a sensor allowed you to increase the working area of the screen. Combining the two fingerprint technologies is not the best idea, as it leads to a general increase in the cost of products, and the location of the scanner on the back side complicates the use.


Touch ID fingerprint sensor provides convenient and reliable protection of personal information. The technology has proven itself well, but the company considered that Face ID is better and more promising in terms of protection, as well as reliability and security. And it is easier to use the new technology, just look at the display at any time of the day, as the screen lock will immediately turn off.

What do you think about Touch ID? Was it worth abandoning advanced technology in favor of Face ID? Share your opinion in the comments at the bottom of the article.

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About the author 

Alex Gustman

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