You probably already know that fingerprint does not provide the maximum security for locking your smartphone, but it is better than PIN or pattern, and it is very convenient especially when you need to unlock your phone quickly. A side note, however, is that fingerprint is NOT protected by the Fifth Amendment, so if you don’t want the law enforcement or the government to peek into your smartphone, then do NOT use fingerprint to unlock your phone. Why? Well, the short answer will be that the Fifth Amendment protects what you know, but does not protect what you have. Biometrics, such as fingerprint and iris, belong to the category of “what you have”, therefore, they fall out of the scope of the Fifth Amendment. If you do use fingerprint to unlock your phone and get pull over by a cop, what do you do? If you have 5 seconds, then either shutdown or restart your phone. When smartphone restarts, it will require you to enter passcode or password first, only then the fingerprint scanner will be enabled. Since passcode or password is protected by the Fifth Amendment, the law enforcement cannot force you to unlock your phone.
Back to the subject. I use fingerprint scan to unlock my Samsung Galaxy S6 just because of the convenience, but recently I noticed the scanner is not working well and keeps giving me “No match” message, then it will ask me to wait for 30 seconds to try again if it fails too many times.
Of course, the first thing I tried was to clean the fingerprint scanner, but it didn’t help. Then I tried to delete the current fingerprint and add a new fingerprint. It would work for a while, then the same problem would mysteriously come back. Very frustrating.
Finally, a support article on Samsung website helped me to fix my problem, and the fix is very simple: just add an additional fingerprint for your same finger. This simple trick seems to greatly increase the accuracy of the fingerprint scanner and I have not had any “No match” error message since adding the additional fingerprint.
Hope this helps if you have the same issue.