Randomized Visual Cryptography to Enhance Security

In visual cryptography, a binary secret image is encoded to produce shares. To increase the security of secret image, it is encoded along with the cover images to obtain shares by random grids method. In this method there is no extra pixel expansion and codebook is not required. The probability parameter β is used to produce the basis matrix and β is varied to check the visual quality of the recovered image. PSNR is calculated for the recovered /decrypted image for different values of β. This scheme improves the quality of recovered image and provides more security.