Iris biometric authentication is gaining importance in recent times. In the overall processing of iris biometric in an iris authentication system, feature processing is an important task. In feature processing, the authors extract iris features, which are ultimately used in matching. Since there is a large number of iris features and computational time increases as the number of features increases, it is therefore a challenge to develop an iris processing system with as few as possible number of features and at the same time without compromising the correctness. It is important that such iris biometrics authentication system be designed to withstand attacks when employed in security critical applications.