Encryption for Sharing of Secret Medical Images

Visual Cryptography Scheme (VCS) is a type of secret sharing scheme which allows the encoding of a secret image into n shares distributed to n participants. Each share constitutes some information and when k shares out of n stack together the secret will reveal. However; less than k shares will not work. The advantage of the visual secret sharing scheme is its decryption process i.e. to decrypt the secret using Human Visual System without any computation. Traditional Visual Cryptography suffers from share identification problem. This problem can be solved by Multiple-Secret threshold visual cryptography (MVCS) which adds a meaningful cover image in each share. The proposed work presents threshold Visual cryptographic schemes in Color Images. This method uses half toning method to provide color image as a secret image. Then the secret image can be embedded in the original image by generating shares using Zigzags scanning method. Experimental result of proposed system provides robust security than conventional visual cryptographic schemes.