Touch ID

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Touch ID was first made by Apple Inc. as a fingerprint recognition security feature on iPhones. It was used to unlock iPhones, make purchases on the Apple Store, and use Apple Pay. Touch ID was first introduced in 2013 with the iPhone 5S, and over time, Touch ID was improved and added to even more Apple products. Although the Touch ID is still used and incorporated in many Apple products today, Face ID, a facial recognition security feature, is used a lot in the new Apple phones. Face ID was introduced in 2017 with the iPhone X and created quite the commotion among many Apple product users.

Touch ID works by using a sensor to pass a small current to the user's finger and create a 'fingerprint map'. This map is then stored in a chip in your phone. This way hackers cannot externally access that information.


History Behind Fingerprints

Touch ID Setup on Mac[2]
Fingerprints are tiny patterns on the tip of our fingers that are completely unique to each person. No two people have ever been found to have the same fingerprints, so they are seen as one of the most secure ways to verify people. Another reason fingerprints are considered a highly secure feature is that they don't change with age and are easily collected from people. Fingerprints form from a result of DNA and environmental factors starting from a baby’s development in the womb. Environmental factors that can affect a person’s fingerprint are as subtle as the nutrition received, umbilical cord length, position in the womb, and blood pressure. Because of this, even identical twins with the same DNA have never been found to have identical fingerprints. [3] The use of fingerprints as a security feature has been most commonly utilized by state prisons, police stations, and even the FBI[4]. The FBI and police use fingerprints to identify suspects and solve different crimes where fingerprints can be found at the scene. Often they use fingerprint identification to decide sentences, probation, and paroles. The way they find fingerprints is often through chemical techniques and then find matches through online programs[5].

History Behind TouchID

In 2012, Apple bought AuthenTec for $356 million and used their technology to build the Touch ID sensors on the iPhone 5S. Once the Touch ID feature was finished and perfected, it wasn't long before companies like Motorola and Fujitsu tried to potentially buy out Apple, but Apple eventually won. In 2013, the iPhone 5S came out with a Touch ID protocol for their iPhones which was used only to unlock the phone. Simply resting your finger on the sensor area will automatically read the fingerprint. In certain scenarios, like rebooting the phone, Touch ID is disabled and the user's numerical passcode is required[6]. A year later, when the iPhone 6 and 6 Plus were released, Touch ID was able to not only unlock the phone, but could be used to make purchases in the App Store, iTunes, and Apple Pay. The Touch ID technology is now on 6S, 6S Plus, 7, 7 Plus, 8, 8 Plus, SE (2nd generation), MacBook Pro, MacBook Air, iPad Pro, and iPad Air. With the more recent Touch ID, you can choose to show details about your notifications only after your fingerprint is read. This way other people who look at your phone can't read your notifications if your iPhone is locked. Now with Facial Recognition rising, it seems that Touch ID's time might be slowly coming to an end. However, its impact on our technological advancements has been revolutionary in the field of technology[7].

The Chip

The Fingerprint data was first stored in the Apple A7 chip in the iPhone 5S, but with new phones came new chips. They are now stored inside the Apple A8, A8X, A9, A9X, A10, A10X, A11, A12, A13, and A14 processors in the iPhones and the T1 and T2 in the MacBook Pro and MacBook Air. Contrary to popular belief, the fingerprints are not stored in iCloud or any place outside the physical iPhone itself.
Image of Find my iPhone[8]

Apple and Anti-theft technology

As one of the leading technology companies, Apple has invested heavily in anti-theft technology. If an Apple device is lost or stolen, touch ID and Find My iPhone work together to offer additional protection against theft[9]. If the iPhone owner realizes their device is missing, there are numerous ways to lock and locate it. Without the iCloud account info, passcode, or touch ID, it is impossible to get into the device unless you have the original box and the iPhone's serial number. If the owner can't locate an iPhone, you can remotely erase your devices to protect their information.

Essentially, Apple has created a general culture that their products, especially their most popular product, iPhones, can't be stolen effectively. This process has coined the term "brick" for iPhones that have been stolen and locked. Unless the original owner deactivates the security protocols and unlocks the devices, it has no viable use other than spare parts.[10]

However, hackers are becoming more advanced by the day, and while it is implausible that a stolen phone would end up in a hacker's hands, it is possible.

In this case, Apple has set another safeguard called the Secure Enclave, which Apple developed to protect your passcode and fingerprint data. Meaning touch ID doesn't store any fingerprint images and instead relies only on a mathematical representation. It isn't possible for someone to reverse engineer your actual fingerprint image from this stored data therefore your biometrics are protected.

Why Do People Use Touch ID

People started using Touch ID because it allows users to quickly unlock their phones. Before Touch ID, to unlock a locked phone, users would need to enter a passcode. This passcode was either a combination of numbers (a PIN) or a combination of characters selected from the alphabet and symbols (periods, question marks, etc.)[11]. It was found that users spend a significant amount of their overall device time entering in their passcode[12]. So, by utilizing Touch ID, iPhones could be more efficient to users and all they need is their fingerprint. And Touch ID can unlock a user's phone in seconds. Additionally, multiple fingerprints can be stored with Touch ID[13]. This makes Touch ID easier to use in that if a user can’t use the original finger that Touch ID was set up with (maybe they broke a finger or it’s dirty) they can use another one of their fingers/fingerprints they set up[14]. In addition, when a user purchases something from the App Store, instead of having to re-enter their passcode as was previously required, users can simply place their finger on the scanner and use Touch ID[14]. And, finally, using Touch ID gives users peace of mind that hackers will have a more difficult time getting into their phones and accessing their information[14]. Because a person’s fingerprint is unique to them, it will be hard, if not impossible, for someone to recreate it. So, essentially, Touch ID is providing users with a stronger passcode unique to them, that doesn’t change over time.

Various Usage of Touch ID

The most commons usage is to unlock your iPhone, iPad, or MacBook devices. However, this function is banned when the user hasn't been using his or her device for 8 hours. In this situation, the user must self-enter the password. Apart from that, Touch ID can also be applied to various scenes. According to Apple, Touch ID can be used to make purchases in App Store and set for Apple Pay. Additionally, if the individual app supports Touch ID, it can also be used to unlock or make purchases on that app. [15] In Apple's Autofill function, which auto-fills the account and password for users, the user needs to first verify their identity using Touch ID.
Apple Pay
The idea of fingerprint biometric locks has been expanded upon into many different products. Many shackle locks are now designed to program the owner’s fingerprint and unlock with it. This design feature eliminates the need for a key and core system and likewise eliminates the possibility for the lock to be picked. Other locks designed with a deadbolt for home door security combine the idea of an electronic lock with fingerprint technology. The internal hardware allows the entering of a passcode as well as a fingerprint to unlock, just like a smartphone. [16] Other examples are lockboxes. These lockboxes can be intended for a variety of applications like gun locks and security safes. Fingerprint gun lockboxes allow users to access their firearms quicker than entering a password. Fingerprint trigger locks provide the same utility. [17]

Electronic Payment

Countries like China have been using their smartphones as vessels for payment. In Shanghai, almost everywhere you go people pay with their phones. It is so common that even all the street vendors have QR codes that take smartphones can scan for payment. Some places do not even take cash payments. Now a shopper can leave home with just their phone. Touch ID, Face ID, or password allows a person to unlock a phone and use any credit cards associated with the phone. The development of new facial technology is also starting to appear in China. Users with the newest iPhone can simply scan their faces and confirm their payment. [18] In the US the development of Apple Pay and Samsung Pay is also gaining in popularity.

Touch ID or Face ID

When Apple launched iPhone X, Apple first introduces Face ID. In the following generations of iPhone or iPad Pro, Apple gradually replaces Touch ID with Face ID. However, Touch ID is still widely used in Apple's product line. Currently, the newest generation of iPad Air, MacBook Pro, and MacBook Air are still using Touch ID. According to Apple, the probability that a random person in the population could look at your iPhone or iPad Pro and unlock it using Face ID is approximately 1 in 1,000,000. [19] In comparison, the probability for Touch ID is 1 in 50,000. Apple says Face ID is a huge improvement in security. However, the actual experience differs in different situations. For example, when a person is wearing gloves, Touch ID would not work because no distortion is generated in the button's electrostatic field. [20] However, under the COVID-19 global pandemic where everyone has to wear masks, Touch ID is easier because one does not need to put his mask off. However, according to BBC, Apple will make Face ID work with masks in the newest update iOS 14.5. [21]

Ethical Dilemmas

Access To Our Information

One of the ethical issues that arise with biometric fingerprinting is the right to privacy. For instance, “Biometric data are personally identifying information. Thus biometric systems have the potential to collect not only pattern recognition information captured by sensors, but also other information that can be associated with the biometric data themselves or with data records already contained within the system.”[22] As a result, the problem arises with what data should be stored and for what purposes. This dilemma gets even more complicated when private companies are allowed to collect your information. For instance, “The GPS Act permits service providers to collect geolocation information in the normal course of business”[23]. Hence, it has become ever more important to know what information is being sent and collected about the user while accessing laptops, phones, smartwatches, etc.

As a follow-up to the concerns mentioned above, the issue arises here regarding informed consent of the user in terms of what they are signing up for because understanding what you are signing up for before giving away sensitive information is an important aspect of a person’s privacy right. “In general, adults are considered to have sufficient ability to understand information. The problem is mainly the child’s informed consent when using biometrics (24). Similar informed consent issues also come from vulnerable populations such as the elderly, mentally ill, and poorly understood people”[24]. Therefore, understanding the terms and conditions before signing up has become important in today’s world.

One of the steps that Apple has taken recently to address some of the issues regarding the storage and retrieval of sensitive information is the use of tokens. For instance, “With Apple Pay, your exact credit card information is never sent over the internet. Instead, a token or random string of numbers representing the card is sent. Biometric tokenization is similar, but it's your biometric data, rather than credit card info, that is obfuscated and transmitted.”[25]

How Secure Is Touch ID?

Touch ID is more secure than Face ID but less secure than password protection. The question is how much sacrificed security is this convenient option than typing in your password every time you need to unlock your phone or sign in to an account? Apple claims the uniqueness of an individual's fingerprint makes this system extremely secure but researchers have recently discovered a new way to break this security barrier. Researchers at Michigan State University and New York University have discovered that because the fingerprint scanners on phones are so small, they only read partial fingerprints--making the images easier to duplicate. Touch ID works by taking about ten different images creating ten partial images of your fingerprint from different angles, never creating one full unique fingerprint image. Therefore, a hacker only needs to match one of these ten partial fingerprint images to unlock the phone. Through the study, using computer simulations, researchers "were able to develop a set of artificial “MasterPrints” that could match real prints similar to those used by phones as much as 65 percent of the time.” [26] Although this is a concerningly high number, these tests were not done with phones. Instead, they were tested on Touch ID systems not connected to phones, making the realistic percentage of replicated prints much smaller. There is concern about the idea that hackers only need to match one of the ten partial prints to unlock your phone but realistically, this is still a very unlikely and difficult thing to do. Although Touch ID is a very secure system, this study highlights some minor weaknesses it presents that could easily be fixed. Most of the researchers were quoted saying they still use Touch ID to secure their phones, but might suggest users use personal password insertion for more confidential log-ins like bank accounts. As technology develops and the importance of smartphones increases with linkage to bank accounts and credit cards, touch ID security becomes a greater issue.

User Accessibility Concerns

Apple has made massive efforts in improving accessibility in recent years. This includes adding categories such as “Vision,” Interaction,” “Hearing,” “Media,” and “Learning” to their “Accessibility” section in their phone settings. However, the release of the iPhone X prompted some concern among the blind/low-vision community [27]. The removal of the home button with the additional Touch ID feature posed some complications with those who relied on the physical feeling of the home button to navigate unlocking their phone.

Luckily, the new Face ID feature has proven to outdo Touch ID at every level in regards to accessibility. First, the set-up process of Face ID is much faster and requires less precision which can be a hindrance to many with limited fine-motor skills. Beyond set-up, Face ID has allowed Apple to make a virtually hands-free experience. The VoiceOver feature has been a vital tool to the blind/low-vision community and this coupled with the Face ID unlocking feature make iPhone products all the more accessible. You still have to occasionally swipe up from the bottom of the screen to the top, but this requires less precision than the former home button/Touch ID as mentioned previously [28].

Although Face ID is generally more accessible, there was previous concern with the “look-to-unlock” feature that requires an active gaze would create a barrier. People with visual impairments or blindness find this task difficult or impossible to do. They also don’t naturally hold the phone up to their face when using them. However, Apple thought this through and allows users to disable this feature by going to Settings > Face ID and Passcodes > Required Attention for Face ID [29]. Apple does say, “Requiring Attention makes Face ID more secure,” but unlike Touch ID which allows multiple fingerprints to be added, only one face can be entered for Face ID [30]. Touch ID is not made with accessibility in mind. Apple went a more inclusive route by creating and implementing Face ID instead.

Touch ID may also not be of use if a person's fingerprint is not identifiable. There are many reasons this could be. For example, wet, wrinkly fingers may not register correctly on Touch ID devices. Medical reasons also may explain the loss of a fingerprint. A 62-year-old man from Singapore was treated for cancer with chemotherapy. He was given the drug capecitabine which led to the peeling of his palms and feet, leaving him temporarily without a fingerprint. US Customs detained him on his travel to visit family in the states and released him after a couple of hours. [31]

See also


  1. “How to Set up Touch ID on Your IPhone or IPad - Apple Support.” YouTube, YouTube, 5 Mar. 2018,
  2. "Use Touch ID on Mac" Apple Support. Web. 17 Apr. 2021.
  3. “Why Twins Don’t Have Identical Fingerprints.” Parenthood, Healthline, 4 Jan. 2019,
  4. Watson, Stephanie (2021). "How Fingerprinting Works" howstuffworks.
  5. The Scientific Research Honor Society (2021). "Crime Scene Chemistry: Fingerprint Analysis" American Scientist.
  6. Apple Inc. (October, 2014). "IOS Security" IOS Security.
  7. Dormehl, Luke. (July 28, 2020). "Today in Apple history: Apple acquires the company behind Touch ID" Cult of Mac.
  8. "Locate a Device in Find My on IPhone." Apple Support. Web. 08 Apr. 2021.
  9. Apple Inc. (2021). "About Touch ID advanced security technology" Apple Inc.
  10. Srinivasan, Avinash, and Wu, Jie. (2012). "SafeCode–safeguarding security and privacy of user data on stolen iOS devices" International Symposium on Cyberspace Safety and Security.
  11. Cherapau, Ivan, and Muslukhov, Ildar, and Asanka, Nalin, and Beznosov, Konstantin. (2015)."On the Impact of Touch ID on iPhone Passcodes" Symposium on Usable Privacy and Security.
  12. De Luca, Alexander, and Hang, Alina, and Von Zezschwitz, Emanuel, and Hussmann, Heinrich. (2015). "I Feel Like I'm Taking Selfies All Day!" Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems.
  13. Bud, Andrew. (2018). "Facing the Future: The Impact of Apple FaceID" Biometric Technology Today.
  14. 14.0 14.1 14.2 Ahmad, Diana Al, and Al, Hadeel, and Hamad, Nada. (2015). "Effectiveness of Iphone’s Touch ID: KSA Case Study" International Journal of Advanced Computer Science and Applications.
  15. Apple Use Touch ID on iPhone and iPad
  16. “Biometric - Keyless Door Locks - Door Locks.” The Home Depot,
  17. “10 Best Biometric Gun Safes In 2021.” Gun Reviews and Buying Guides, 28 Jan. 2021,
  18. World Leaders in Research-Based User Experience. “Case Study of Facial-Recognition Payment in China.” Nielsen Norman Group, 10 May 2020,
  19. Apple "About Face ID Advanced Technology"
  20. William Judd "The iPhone home button won’t work with gloves"
  21. "Apple Face ID to work for mask wearers BBC News
  22. National Research Council. (2010). [ “Read ‘Biometric Recognition: Challenges and Opportunities’ at”] National Academies Press: OpenBook.
  23. U.S. Senator Ron Wyden of Oregon. [ “GPS Act”] Ron Wyden United States Senator for Oregon.
  24. Cooper, Isaac. (September 2019). [ “(PDF) Ethical Issues in Biometrics”] ResearchGate.
  25. Simic, Bojan. (25 Sept. 2017). [ “Council Post: The Promise And Challenges Of Biometrics”] Forbes Magazine.
  26. Goel, Vindu (April 10, 2017). "That Fingerprint Sensor on Your Phone Is Not as Safe as You Think" The New York Times.
  27. Thompson, Terrill. (2018). [ “iPhone X and Accessibility | AccessComputing”] AccessComputing.
  28. Aquino, Steven. (21 Nov. 2017). [ “What Face ID Means for Accessibility”] Steven’s Blog.
  29. RightPoint. (6 Dec. 2017). [ “The iPhone X: What Does Face ID Mean for Accessibility?”] Rightpoint.
  30. Ingber, Janet. (Feb. 2018). [ “The iPhone X for People with Visual Impairments: Face ID, New Gestures, and Useful Commands | AccessWorld | American Foundation for the Blind”] American Foundation for the Blind.
  31. Harmon, Katherine. “Can You Lose Your Fingerprints?” Scientific American, Scientific American, 29 May 2009,