Fact sheet: Apple Touch ID

Erik Eckel lists the facts surrounding Apple Touch ID.

Apple Touch ID

This fact sheet will be continually updated with the latest details as we learn more about Apple Touch ID. You can check back and refresh this article to receive the latest updates.

What we know

  • iOS version: Touch ID requires iOS 7.
  • Compatible hardware: Touch ID works with the Apple iPhone 5S.
  • Availability: September 20, 2013.
  • Base price: Touch ID technology is included with the Apple iPhone 5S.
  • What is it?: Touch ID is biometric technology new iPhone models leverage, enabling authorized users to unlock the phone and make purchases within iTunes and the App Store using a fingerprint.
  • How does it work?: The iPhone 5S’s new home button scans users' fingerprints and converts them to digital signatures.
  • Can more than one finger be used?: Yes. Users can scan multiple fingers, and multiple users are supported on the same device.
  • Does Apple receive copies of users’ fingerprints?: No. Fingerprint images are converted to digital signatures. The digital signatures are then encrypted for security purposes. The fingerprint image signatures are actually stored encrypted within the iPhone 5S’s A7 processor. The fingerprint information is available to no other process or program other than the Touch ID sensor.
  • Is the Touch ID fingerprint digital signature backed up to iCloud?: No. The digital signature is never available to other software or backed up to Apple’s iCloud.
  • What if I injure my finger?: Users wearing Band-Aids or suffering other injury can still choose to unlock the Smartphone and make purchases using traditional passcodes and passwords.
  • Why did Apple introduce the technology?: Touch ID enables users to unlock their phones (a task most users repeat dozens of times or more per day) much more quickly than when using a password. Using a unique fingerprint is also more convenient and enables users to make secure purchases more easily. Apple Senior Vice President of Design, Jonathan Ive, says, “Touch ID defines the next step of how you use your iPhone, making something as important as security so effortless and so simple.”
  • Does a finger need to be placed on the home button using the same orientation each time?: No, the Touch ID technology enables reading fingerprints from any orientation, meaning users can program their fingerprint signatures holding the iPhone upside down and still unlock the phone by placing the finger on the home button when the iPhone is upright.
  • How does the Touch ID sensor work?: The technology uses what Apple describes as Advanced Capacitive Touch to take a high-resolution image of the finger from the skin’s subdermal layers. Prints are recorded with remarkable levels of precision and detail, according to Apple. Fingerprints are categorized into one of three types (arch, loop, or whorl). The Touch ID button itself is made from Sapphire crystal, which protects the sensor and acts as a lens to precisely focus on the finger.
  • How long does the touch sensor take to read a fingerprint?: Apple demo videos suggest the iPhone 5S reads fingerprints in approximately one second.
  • Are iPhone 5S users more likely to lose fingers during iPhone thefts?: Security experts believe Apple’s fingerprint scanning technology senses whether a digit is attached to a living human, so severed phalanges should prove unsuccessful for unlocking a stolen iPhone.