Selective Region Based Image Encryption

Abstract

With the extensive use of the multimedia data over the insecure open natured channels the security of the multimedia data has become very important. There are several encryption techniques for the secure transmission of the images. Encrypting a whole image can make the image information useless for unauthorized access but this whole image encryption of image will increase the computation time of encryption and decryption. To reduce this increase in computation time for encryption/decryption, an approach called selective encryption has been introduced in several new works. With selective encryption considerable reduction in the computation cost can be achieved. This approach however, needs to be explored further for its practical application. We have also found that permutations used in the scheme needs to be revised to obtain better security. The aim of this thesis is to give an efficient image encryption scheme using region based selective encryption. In this paper a new approach is introduced that will select sensitive area for encryption based on percentage of coefficients and then encrypting the selected area with AES algorithm. To further enhance the security of the image the un-encrypted area is permuted with the encrypted area. The Peak Signal-to-Noise Ratio, PSNR values show a huge difference between the original image and the encrypted image.