Implementation of Random Grid Visual Cryptography for Color Images

Visual Cryptography is a special encryption technique that encrypts the secrect image into n numbers of shares to hide information in images in such a way that it can be decrypted by the human visual system. It is imperceptible to reveal the secret information unless a certain number of shares (K) or more are superimposed. Simple Visual Cryptography is very insecure. Variable length key based Visual Cryptography for color image uses a varible length Symmetric key based Visual Cryptography scheme for color images where a secrect key is used to encrypt the image and division of the encrypted image is done useing Random Number. Unless the secrect key is known, the original image will not be decrypted. Here secrect key ensures the security of images. The proposed method introduces the concept of above scheme. Encryption process encrypts Original Image using variable length Symmetric key, gives encrypted image. Share generation process divides the encrypted images into n number of shares using random number. Decryption process stacks k number of shares out of n to reconstruct encrypted image and uses the same key for decryption.