How to build a biometric recognition with a given specification?

Dear All,

How can I build a biometric recognition system with a given False Acceptance Rate or False Rejection Rate?.for example if I am asked to build a biometric recognition system which can give an FAR of 10%.How can I built.just give me an idea.

[Nitin]

You first need the intra and the interclass distribution. Then you can set a threshold with FAR 10%

This diagram should makes things clearer http://postimg.org/image/ckrao1cp5/

[faa nad]

thanks for your reply...