Biometric authentication in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is biometric authentication in Android?

Biometric authentication uses a person's unique physical traits, like fingerprints or face, to verify their identity securely on Android devices.

beginner

Which Android class helps implement biometric authentication?

The <code>BiometricPrompt</code> class provides a simple way to show a system dialog for fingerprint, face, or iris authentication.

intermediate

What is the purpose of BiometricManager?

It checks if the device supports biometric authentication and if the user has enrolled any biometric credentials.

intermediate

Why should biometric authentication be combined with fallback options?

Because not all users have biometric data enrolled or sensors available, fallback like PIN or password ensures everyone can access the app securely.

beginner

Name two common biometric types supported on Android devices.

Fingerprint and face recognition are the two most common biometric types supported on Android devices.

Which class do you use to show the biometric authentication dialog in Android?

A AuthenticationManager

B BiometricManager

C FingerprintManager

D BiometricPrompt

BiometricPrompt is the official class to display the biometric authentication dialog.

What does BiometricManager.canAuthenticate() do?

A Checks if biometric hardware is available and user has enrolled biometrics

B Requests biometric permission from the user

C Starts the biometric authentication process

D Deletes enrolled biometric data

BiometricManager checks hardware availability and enrollment status.

Why is it important to provide a fallback authentication method?

A Because biometric sensors can fail or be unavailable

B Because biometric authentication is always slow

C Because fallback is required by Android policy

D Because fallback is more secure than biometrics

Fallback ensures users can still access the app if biometrics fail or are not set up.

Which biometric types are commonly supported on Android devices?

A Face recognition and voice

B Fingerprint and face recognition

C DNA and fingerprint

D Voice and retina scan

Fingerprint and face recognition are the most common biometric types on Android.

What is the first step before starting biometric authentication?

A Show the biometric prompt immediately

B Request camera permission

C Check if biometric hardware is available and biometrics are enrolled

D Clear all biometric data

You must check hardware and enrollment before prompting for biometric authentication.

Explain how to implement biometric authentication in an Android app using Kotlin.

Think about the sequence from checking device capability to showing the prompt and handling results.

Why is biometric authentication considered more user-friendly than passwords, and what are its limitations?

Consider both benefits and practical challenges of biometrics.