Touch ID fingerprint scanner
Touch ID is the name of the fingerprint sensor in the iPhone, iPad, and some MacBook models. The sensor is incorporated in the home button below the screen on the iPhone and iPad, while it can be found on the MacBook right above the keyboard, for example as part of the Touch Bar.
- Touch ID on iPhone and iPad
- That is how it works
- Touch ID features
- Touch ID security
- Password obsolete?
- Touch ID cons
- More tips on Touch ID
This is how Touch ID works on the iPhone and iPad
The home button (home button) of the iPhone and iPad has multiple functions, such as activating Siri or switching between apps. Since the iPhone 5s, a new function has been added: the fingerprint scanner.
You will find Touch ID on the following devices.
iPhones:
- iPhone 5s
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iPhone 6 (Plus)
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iPhone 6s (Plus)
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iPhone 7 (Plus)
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iPhone 8 (Plus)
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iPhone SE (all generations)
iPads:
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iPad 2017 and newer
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iPad mini 3 and newer (from 6th generation in the side button)
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iPad Air 2 and newer (from 2020 in the side button)
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iPad Pro 2015 and 2017 (from 2018 with Face ID)
Touch ID: That’s how it works
The Touch ID button contains sensors that recognize touch and then scan your fingerprint. The ring around the home button plays a crucial role in this: if this ring recognizes changes in electrical voltage, the sensor knows that you have placed your finger on it. If the Touch ID sensor is incorporated into the side button, it works in a similar way. This button is made of metal and can also measure a change in electrical voltage.
Then the sensor behind the button comes into action. They make a depth image of the skin layers, including all imperfections. So you don’t have to press the button, a light touch is enough. Touch ID can recognize your finger from different angles. It is therefore not necessary to place your finger flat or exactly at an angle of 0 degrees on the button.
Before Touch ID works, you will first have to set up one or more fingers. You can register up to 5 fingers of yourself, or possibly a partner, children or a good friend.
The Touch ID scanner creates a high-quality 3D representation of your fingerprint, which also looks at deeper skin layers. So you can’t fool the system by copying a fingerprint from a beer glass. Touch ID is also self-learning: every time you make a new scan, the registration of your fingerprint is improved, so that your finger is recognized faster and faster. Besides your thumb, you can also use other fingers. There are even people who have registered their nose.
Not sure whether you want an iPhone with Touch ID or Face ID? We have made a comparison in which we list all the differences for you! Both have advantages and disadvantages.
Since the iPhone 6s, most of Apple’s devices have used the improved second-generation Touch ID sensor. It recognizes a placed finger even faster, so you can unlock your iPhone even faster.
Touch ID features
Touch ID has several functions. You can use it to unlock your iPhone or iPad, so that you no longer have to enter the passcode every time. You can also use it for purchases in the App Store and payments with Apple Pay, instead of a password. This allows you to give permission for certain transactions more quickly, without having to enter your password every time. For security reasons, you must enter your access code once again when restarting your device. So you still have to remember this code.
Touch ID in third-party apps
Initially, Touch ID only allowed you to unlock your iPhone and make App Store purchases. Since iOS 8, more is possible: apps from third-party developers can also use Touch ID. For example, you can make payments, log in to your own bank’s app or unlock your password management app. Since iOS 9.3, you can also use Touch ID in Apple’s Notes app to protect written texts. This is useful if you keep private information in notes. You can choose which notes are or are not protected with Touch ID.
App developers must build in support for Touch ID themselves. Apple underlines that developers will not have access to the fingerprint data itself. They can only have iOS perform a check, without revealing any data.
The password app 1Password is a good example of an app with Touch ID. In 1Password you can save passwords for websites and other apps, which are protected by your fingerprint. This means that you only have access to the passwords. In addition to your fingerprint, a ‘regular’ password is also used, in case the recognition of your finger does not work.
Another good example are the apps of various banks. You can use your fingerprint to log in and to send payments.
If you also register your partner’s fingers, be aware that this person has access to all apps that use Touch ID. He or she can therefore not only unlock your device, but also view your bank details and read notes.
Mobile payment: Touch ID and Apple Pay
With Touch ID it is possible to make mobile payments in stores. Apple’s payment service Apple Pay is used for this. You hold the iPhone against a suitable payment terminal, put your finger on the home button and the transaction is carried out automatically. Apple Pay requires at least an iPhone 6 or iPhone 6 Plus, or an Apple Watch. On the iPad, you can only use Apple Pay in the apps themselves and not in stores.
Touch ID: safe or not?
Broadly speaking, there are two ways to scan a fingerprint: optical and capacitive. With an optical reader, a photo is taken with a digital camera. These optical systems are easier to fool, for example with a good photocopy or photo. Greasy fingers on the glass plate can lead to errors more quickly.
This is not the case with Touch ID: a capacitive reader has been chosen there. It takes advantage of the fact that the outer layer of your skin is non-conductive, while the deeper layers do conduct electricity. When you touch the Touch ID sensor, it measures the structure in skin layers. Based on this, a 3D image is created.
Apple has provided even more security measures. For example, all fingerprint information is encrypted and stored locally in the Secure Enclave. This information is not accessible to installed apps, nor is it sent to Apple’s servers or to iCloud. Your fingerprint can therefore never be retrieved in the event of a future hack of iCloud. According to Apple, there is a 1 in 50,000 chance that the finger scan will be misinterpreted and someone will still be able to access the iPhone. With Face ID, this chance is much smaller.
Apple does not store the pattern of your finger or a 3D model of your fingerprint, but makes a calculation of which only the result is stored. When you scan your finger, this calculation is performed again. If this yields the same result, you will be granted access.
You can register multiple fingers with Touch ID.
Password redundant due to fingerprint?
Fingerprints are much more secure than passwords. There is so much variation in fingertip patterns, creating an infinite number of possibilities and making it impossible to guess a fingerprint. Fingerprint scanning is also much more user-friendly than entering a password.
There is also a disadvantage: while you can easily replace your password after a hack, this is not the case with a finger scan. You are stuck with the same finger patterns for the rest of your life. Another disadvantage is that fingerprints are a form of single-factor authentication. You only need one item (the fingerprint) to gain access. More secure systems always involve two-factor authentication, for example a fingerprint and a password. When you sleep, someone can unlock your iPhone by holding the home button against your finger.
Passwords will probably never disappear, because a backup is always needed if the sensor breaks or fails.
Touch ID: Enter password after 48 hours
An iPhone or iPad that has not been unlocked for 48 hours or more will still ask for a passcode. A code must also be entered after a reboot. With these exceptions, Apple wants to make it more difficult for thieves to unlock a stolen iPhone.
The 48-hour rule ensures that they have less time to try to circumvent security. After five failed scan attempts, the operating system also asks for an access code. The same happens if your device is locked remotely with Find My iPhone.
Touch ID not working? This is usually because you have not used your device for more than 48 hours or have just restarted the device. It’s very rare for Touch ID to break.
Disadvantages of Touch ID
Touch ID works flawlessly in the vast majority of cases. The sensor is made in such a way that it can quickly and easily scan your finger, even if it is not lying flat on it. The scanner does have difficulty with damp fingers, for example due to sweat or water. For example, if you have been in the shower for a long time, you will notice that the sensor will not immediately recognize your fingerprint because your skin has become wrinkled.
Tattoos and fingers with scars and other imperfections may also work less well in combination with the Touch ID sensor. It is therefore best to set up an undamaged finger for use with Touch ID.
If you have a problem scanning the Touch ID sensor, it is best to reset Touch ID on your iPhone or iPad.
More tips on Touch ID
Also read our other tips about Touch ID:
- Name Touch ID fingers to make them easier to identify
- This way you can find out which Touch ID fingers you have registered
- Here’s what you can do if Touch ID isn’t working on your iPhone
- This way you can quickly disable Touch ID
