How do you test fallback mechanisms for unsupported devices?

Fallback mechanisms are critical to ensuring a seamless authentication experience when passkeys are unavailable or unsupported on certain devices. Here's how to effectively test these mechanisms:

• Unsupported Devices: Test on older devices or browsers that lack WebAuthn support.
• User Error Cases: Simulate scenarios where users cannot access their passkeys, such as device loss or unavailability.

• Password Fallbacks: Verify that users can log in using their credentials if passkeys are unavailable.
• One-Time Passwords (OTPs): Test SMS or email-based OTP workflows to ensure they function correctly.
• Security Questions: Validate usability and security for fallback methods like recovery questions, if implemented.

• Network Disruptions: Test fallback mechanisms under poor or no network connectivity.
• Multiple Fallbacks: Simulate situations requiring sequential fallbacks, such as switching from passkeys to OTPs and then to passwords.

• User Guidance: Check that fallback workflows provide clear instructions to users.
• Error Messaging: Ensure error messages are informative and direct users to alternative authentication options.

• Prevent Abuse: Ensure fallback mechanisms cannot be exploited to bypass primary authentication.
• Session Integrity: Validate that fallback methods maintain session security and do not compromise user credentials.

• Compatibility: Test fallback options across multiple devices, operating systems, and browsers.
• Consistency: Ensure fallback workflows behave uniformly across supported platforms.

• Analytics: Track usage data for fallback mechanisms to identify common pain points.
• Iterative Testing: Continuously refine fallback workflows based on user feedback and test results.

By thoroughly testing fallback mechanisms, you can ensure a robust and user-friendly authentication experience, even for users on unsupported devices.