Image Encryption using (k, n) Secret Sharing Scheme using Lagrange Polynomial

In this project a new (k, n) secret sharing scheme for image encryption is used. The proposed method encrypts the secret image into two images which are of the same size as that of the original image, in which one image is the public image (called the encrypted image) and another image is to be shared among n participants employing a new secret sharing method supported by the Shamir?s secret sharing. In the new secret sharing scheme, k (or more) shares secretly held by the participants could reconstruct the shared image, where the size of each share is 2 (logkm)/m2 of that of the shared m*m image. Then the secret image can be recovered by using the encrypted image and the shared image without any loss. Further, the size of the shares can become smaller by partitioning the secret image into many smaller blocks and encrypting all these block images into a public encrypted image as the same size of the secret image. Compared with the previously known image encryption techniques based on the secret sharing, the size of the shares in our technique is smaller with the same size as that of original image.