A biometric authentication system operates by acquiring raw biometric data from a subject e.g., fingerprint and iris images. This original raw data is stored in the central database. Preserving the privacy of this digital biometric data has become very important. Visual cryptography can be applied to securing this information. The proposed work preserves the privacy fingerprint and iris-based authentication using Inverted Share image Visual Cryptography (ISVC). In ISVC, we invert one share image and stack it with another shared image to obtain the extra confidential data that can be used for authentication. In traditional visual cryptography, the size of the recovered image is expanded because of pixel expansion during encryption. This also leads to recovered image distortion. Therefore, the proposed scheme combines a non-expanded scheme with the extra ability to hide biometric data, such as fingerprint and iris image, in some cover image to maintain privacy. This will also solve the pixel expansion as seen in traditional visual cryptography