Biometric information need to be transformed and converted into template file. The data is then encrypted and stored in a secure server in a data center or cloud environment.
This is a very vague question. If you seek for a general approach, please utilize examples such as that at http://www.csjournals.com/IJCSC/PDF4-2/44.%20Sheetal.pdf!
1- If the data is stored in the Cloud, sure it is not secure.
2- if the data is stored in a local server, then 90% is secure but the administrator can retrieve data if the encryption is well known. the solution here is to ask the provider of the machine or software "what is the type of encryption for data?
The solution is using HASHING Function.
"Hashing is a one-way function where a unique message digest is generated from an input file or a string of text. No keys are used."
3- don't forget about Network security.
My solution to be safe around 99% is:
1- Using a Peer-to-Peer network between the Machine and the local server without using a switch or router in the network.
2- Using Hashing function and NOT a normal Encryption.
Biometric data is 1FA, in that it contains both your user ID and password. Once it is digitised, it is just like any other username/password system, but marginally faster (if that's important to you) but, if stolen, can be used in replay attacks on all the victim's accounts. Unlike the username/password system it seeks to replace, if it is stolen, changing credentials can be rather painful, if not impossible. Systems which try to make it 2FA, by hashing the second factor with the biometric data, merely end up with a more complex 1FA system.