Using a fingerprint to Authenticate to Remote Servers

The release of Marshmallow brought with it the ability to use fingerprints to authenticate a user's identity. If you're a developer making an application that features online purchasing, then you might be interested in learning how to implement an asymmetric keypair in order to grab a public key to store in your server's backend, allowing you to authenticate future purchases using only the customer's fingerprint.

source: xdadevelopers