Any ideas on how to secure fingerprint images with use of steganography?

Hi, I am working on my MSc project based on fingerprint security. To date, I have developed a fingerprint system and I am now at the stage that I want to implement some security, using steganography.

I was thinking of embedding a 4 digit passcode by way of DWT steganography. Any comment/help/advise would be greatly appreciated. I want to mention that I am not posting here to get code and get the work done for me, I am only asking for advice.

I have only starting using matlab a few months ago and have developed the minutia extraction process of my fingerprint system, with the help of mathworks documentation,which I find is excellent!

It is an exciting time for me learning a new programming environment etc. Thank you in advance