IMAGE ENCRYPTION USING ADVANCED COMBINATION OF PERMUTATION TECHNIQUE TO REDUCE CORRELATION AMONG NEIGHBORING PIXELS

Images occupy the most important position in multimedia data. Techniques for transmitting and storing images are increasing to a greater extent. Images that are transferred over the network are confidential and private. Therefore there is a need for protecting these image data from the unauthorized users. This is achieved using Image Encryption. There are many techniques used to protect the image data. Most of the existing Image Encryption and Decryption techniques perform image encryption by scrambling the pixels or by dividing the images into blocks and shuffling them or by permutation. Images are arrangement of pixels and the image information can be predicted from the value of the neighboring pixels. Therefore it is important to decrease the correlation among the neighboring pixels and increase the entropy. The proposed work deals with decomposing the image into block size of very smaller pixels, and the image blocks are scrambled using the proposed permutation technique, which will result in lower correlation and higher entropy. The permuted image obtained is encrypted using RSA algorithm. Preprocessing of the image is carried out, by converting the binary values of the image into Integer which makes easy to work with RSA algorithm for the encryption of the image. Permutation on the smaller blocks of the image itself has provided security to the images, further when encryption is applied on this permuted image a higher level of security has been achieved. Computational Hardness and great security has been provided by RSA algorithm.