[AC Question]

I want to make an android application, which registers user fingerprint (from device's fingerprint scanner) and stores it in a data structure or in key store provider, next time user put his fingerprint scanner, he should be authenticated from the fingerprints stored in the data structure or from the Android Keystore provider. If anyone can help me how to approach for this.

(In settings I can only register limited number of users, so I want my application to register users fingerprint)

[hallux]

Why not utilize the API Google has implemented for fingerprints? That makes it easier as it ties in at an OS level.

Also - I suggest registering and posting in the developers section of the site, you can better target the audience that is best able to help you with these types of questions. See this link for instructions on how to join Android Central.