Securing the Images Using Biometric Cryptography Technique

A biometric authentication system operates by acquiring raw biometric data from a subject, extracting a feature set from the data and comparing the feature set against the templates stored in a database in order to identify a person or to verify a claimed identity. The template data in the database is generated during enrolment and is often stored along with the original raw data. This work explores the possibility of using visual cryptography without pixel expansion for imparting privacy to biometric data such as fingerprint images, iris codes, and face images. In the case of faces, a private face image is dithered into two host face images that are stored in two separate database servers such that the private image can be revealed only when both sheets are simultaneously available; at the same time, the individual sheet images do not reveal the identity of the private image. Two schemes such as Multiple Secrets without pixel expansion and Multiple-level visual secret-sharing scheme without image size expansion. The First approach has the three phases for encryption scheme such as dividing and separating process, sticking process and camouflaging with maximum block density process. The Second approach uses histogram widthequalization and histogram depth-equalization. Histogram depth equalization is used to obtain better reconstructed secret image.