I'm trying to understand how to implement bio-metric authentication on an app, specifically using a fingerprint.
From what I understood so far the API only provides 3 different information: auth failed, auth success and no fingerprint registered in device.
I am not trying to get any information from the user's bio-metric data, but I cannot find anywhere explained how to relate a user's bio-metric information with his login.
So far I can only think of a way that I could make this work and that would be to require a first time registration before being able to use fingerprint in future logins in which the following takes place:
- User enters login data in a form (name and password, for example)
- Using the fingerprint success response that information is stored locally after verifying if the login data is correct on the server side
Problem with this is that the user's credentials are vulnerable now since it is stored locally and although I could use my own encryption process I fear it would not be more secure because I'd still need to store the encryption algorithm locally with the app in order to encrypt/decrypt that information.
How can I associate the user's bio-metric data / auth success with his login credentials?