ASP - Biometric Authentication

Cheers,

We started implementing biometrics authentication in our web system and came to a doubt. We're going to use a third-party solution for performing it which is going to be called via a web service.

There are going to be four kinds of authentication:

Regular one: username/password
Challenge
Fingerprint
Cellphone

All users will be authenticated using 1. Optionally, some of them may also require 2, 3 or 4. What would be a good way of verifying which authentication type is required for a specific user?

This is something new for me. Initially, I thought about passing the username from the login page to a web service, which would query the database to check which authentication type is required for this user. Then, depending on the result, the second authentication form would be shown on the screen. Obviously, some extra check would be performed after the user hit the Submit button.

Am I on the right path, or there are better solutions for this?

Thanks,

I guess that would work. Maybe it is an option to do some sort of query in the background (AJAX?) when the username is filled in, so you can dynamically add extra inputs to your login form.

However, this has one potential issue: everybody that knows someone 's username can find out what authentication is required. If that is not wat you want, maybe just ask for a username + password to login to a reduced privelege mode. Then, as you suggested in your question, this reduced privelege mode may require extra credentials to continue to the more secure environment.

You could even make it so the reduced privelege mode will grant access to some of the features, while others require extra authentication (for example: posting a mesage would require basic auth, changing passwords might require all four).