VISUAL CRYPTOGRAPHY AND STEGANOPGRAPHY: A REVIEW

Information sharing and transmission is increasing day by day, information gets more value when shared. Due to rapid development in networking and communication technologies, it became easy to share the multimedia information. It may give rise to security related issues. Attackers may try to access the information and misuse it. To address this problem certain techniques are required to increase security. Visual cryptography (VC) is a technique used for protecting secrets using images, Visual Cryptography is an encryption technique used to hide information in an image in such way that only those can decrypt the images who has secret key. The basic concept of visual cryptography scheme is, to split secret image into some shares. Shares are then distributed to receiver side. By stacking these shares directly, secret information can be revealed and visually recognized by authorized person. Steganography is an art, science or practice in which messages, images or files are hidden inside other messages, images or files. All shares are necessary to combine to reveal the secret image. Starting from the basic techniques, many visual cryptographic techniques have been developed.