How to Properly Test Biometric Authentication for Mobile Apps
Biometric authentication has become an increasingly popular way for mobile apps to verify a user‘s identity. By scanning a fingerprint, recognizing a face, or processing an iris or voice pattern, biometric authentication offers convenience, security, and ease of use.
However, comprehensively testing biometric authentication can be complex. This guide will provide mobile testers with best practices for properly evaluating biometrics in apps across key methods like fingerprint scanning, facial recognition, and more.
Common Biometric Authentication Methods
There are several biometric techniques used for authentication in mobile apps:
Fingerprint Scanning
Fingerprint authentication is currently the most widely adopted method. It verifies a user by scanning their fingerprint and matching it to a registered template. Testing needs to account for varying fingerprint quality, scanning angles, pressure, and more.
Pros: Highly accurate and fast method. Provides good security and convenience.
Cons: Requires a fingerprint scanner hardware component. Fingerprints can degrade over time.
Facial Recognition
Facial recognition uses advanced image processing to map facial features and match them to images in a database. Testing needs to cover diverse lighting, angles, accessories, and facial changes.
Pros: Convenient hands-free authentication. No additional hardware needed in modern devices.
Cons: Can be spoofed more easily than other methods. Accuracy impacted by conditions and changes.
Iris Scanning
Iris scanning analyzes the unique patterns in a person‘s irises using an infrared light. Testing focuses on scan angles, lighting, image quality, and iris obstructions.
Pros: Extremely accurate with very low spoof rates. Unique to each person with no significant changes over time.
Cons: Requires specific camera and lighting components. Users find iris closeup scanning uncomfortable.
Voice Recognition
Voice recognition uses a microphone to capture a voice sample, then extracts and matches voice pattern biometrics to a registered voice print.
Pros: Convenient and hands-free. No additional hardware required.
Cons: Can be impacted by ambient noise and audio quality. More vulnerability to spoofing.
Key Considerations for Testing Biometric Authentication
Thoroughly testing biometric authentication requires attention in several areas:
Using Real Devices
Due to the hardware and software dependencies, biometric testing on simulators or emulators will be very limited. Real iOS and Android devices with appropriate biometric capabilities are essential.
Cloud Testing Access
Since acquiring every device variant is impractical, leveraging cloud testing platforms like BrowserStack App Live that provide instant access to real mobile devices can efficiently scale test coverage.
Cross-Platform Testing
Testing needs to cover both iOS and the fragmentation of the Android ecosystem across various devices, OS versions, and manufacturers.
Combining With Other Authentication
In most apps, biometrics will complement an existing login flow using passwords or PINs as part of multi-factor authentication. This interaction requires integration testing.
Testing Fingerprint Scanner Authentication
For fingerprint scanning, some key aspects to test include:
Scanning Angles and Pressure
Test scanning fingerprints at different rotational angles and pressure levels to ensure consistent recognition. Account for both flat and upright device orientations.
Wet and Dry Fingers
Evaluate fingerprint matching with fingers that are wet, sweaty, or dirty to confirm it can handle real-world conditions.
Fingerprint Quality
Authentication needs to work reliably even for worn fingerprints with faded ridge details from users doing manual labor or jobs causing fingerprint deterioration.
Recognition Speed and Accuracy
Users expect fast and accurate recognition of their fingerprint by the biometric sensors and security algorithms. These need quantification via performance testing.
Failed Attempts and Lockout
Confirm failsafes allow a limited number of attempts before locking out and requiring alternative authentication. Test the account recovery flow for re-enabling fingerprint sign-in after lockouts.
Conclusion
Biometric authentication introduces new complexity for mobile testers but also higher security and usability for app users. Following best practices around cloud access, devices, test case diversity, and more allows testers to fully evaluate the reliability, accuracy and performance of biometric experiences in mobile apps. Comprehensive testing is crucial for building user confidence and trust in this technology.