11-05-2012, 03:56 PM
Lossless Encryption for Color Images using a Binary Key-image
27.IJAEST-Vol-No-9-Issue-No-2-Lossless-Encryption-for-Color-Images-using-a-Binary-Key-image-314-321.pdf (Size: 605.36 KB / Downloads: 78)
INTRODUCTION
Cryptography is, traditionally, the study of means of converting information from its normal, comprehensible from into an incomprehensible format, rendering it unreadable without secret knowledge-the art of encryption. The first visual cryptographic technique was pioneered by Moni Naor and Ad Shamir in 1994. It involved breaking up the image into n shares so that only someone with all n shares could decrypt the image by overlaying each of the shares over each other. Practically this can be done by printing each share on a separate transparency and then placing all of the transparencies on top of each other. In their technique n-1 shares revealed no information about original image.
The EdgemapCrypt algorithm for 2D image
This algorithm described in Fig. 2, generate the key-image from another new/existing image with the same size as the original image using the specific edge detector with a selected threshold value. The key image is considered as the edge map. The edge map is frequently used in image enhancement, compression, segmentation and recognition. The applications of edge map can also be extended to image encryption.
The EdgemapCrypt algorithm for 3D image
The edge map is frequently used in image enhancement, compression, segmentation and recognition. The application of edge maps can also be extended to image encryption. An edge map is considered as the key-image in this algorithm. The edge map is generated from new/existing image for color or grayscale image with same size as the original image using the specific edge detector with a selected threshold value.
EXPERIMENTAL RESULTS
Different 2D and 3D images such as grayscale images, color images and animal images have been successfully implemented for Lossless encryption algorithms. The simulation results are provided to show the performance of the algorithms for 2D and 3D image encryption.
CONCLUSION
We have introduced Lossless Encryption for Color Images using a Binary Key-image. We also introduced two image encryption algorithms based on this key-image. To generate key image an either a bit plane in the BitplaneCrypt or an edge map in the EdgemapCrypt algorithm.
The grayscale images and color images are fully encrypted from both algorithms the completely reconstruct the 2D images and 3D images without any distortion from the original image. The BitplaneCrypt and EdgemapCrypt algorithms have extremely large security key space for the cryptography point of view and can withstand most common attacks search as the plaintext attacks and brute force attacks and ciphertext attacks.