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androidencryptionfingerprintandroid-securityandroid-fingerprint-api

Android Fingerprint only allows 5 attempts at a period of time


I am developing an Android App that requires fingerprint to open an Activity. I just noticed when I unlock my phone using my fingerprint, the number of attempts to scan a fingerprint in my app only becomes 4.

For example:

  • Phone is locked

  • Unlock phone using fingerprint

  • Open my fingerprint app

  • Cannot attempt to scan a fingerprint more than 4 times

Another scenario:

  • Fingerprint app is open

  • Only 5 attempts will be accepted, app will no longer attempt to scan a fingerprint

  • Wait for a period of time, again, only 5 attempts within a duration will be accepted

Is there a workaround for this?


Solution

  • I did some research and found the Android 6.0 Compatibility Definition Document.

    This was stated under the Fingerprint Sensor section:

    Device implementations with a secure lock screen SHOULD include a fingerprint sensor. If a device implementation includes a fingerprint sensor and has a corresponding API for third-party developers, it:

    MUST rate limit attempts for at least 30 seconds after 5 false trials for fingerprint verification.

    So.. I guess there's no workaround for this at the moment.