Study of Perfect Shuffle for Image Scrambling

In recent years, Digital data transmission has increased, providing security to this digital data is of high importance. As a result, people pay much more attention to image encryption. Many approaches for image encryption that have high security as well as simple encryption process have been proposed. In this paper, Perfect shuffle for image scrambling is introduced. Effects of perfect shuffles with different factors of the image size are discussed. The number of iterations required to get back the original image are related to the power of 2. Finally all these results are displayed by using 1024 X1024 Lena's image. mage scrambling is a useful approach to secure the image data by scrambling the image into an unintelligible format. (1) introduces a new parameter based M-sequence which can be produced by a series shift registers. In addition, a new image scrambling algorithm based on the M-sequence is presented. The user can change the security keys, r, which indicates the number of shift operations to be implemented, or the distance parameter p, to generate many different M-sequences. This makes the scrambled images difficult to decode thus providing a high level of security protection for the images. The presented algorithm can encrypt the 2-D or 3- D images in one step. It also shows good performance in the image attacks such as filters (data loss) and noise attacks. The algorithm can be applied in the real-time applications since it is a straightforward process and easily implemented. (2) presents a novel image scrambling method using Poker shuffle, which is controlled dynamically by chaotic system. Compared with other scrambling techniques such as algebraic permutations and chaotic permutations, the proposed method has properties of nonlinearity, non-analytic formula and large key space. Moreover, its scrambling performance is satisfied and can deal with non-square image. All these features show that the proposed method is more secure and efficient for image scrambling encryption. There are many methods for calculating the periodicity of Arnold transformation and getting the inverse transformation, the use of traditional Arnold transformation for the image scrambling is unsafe, for this issue (3) proposed an algorithm for digital image block location scrambling. It has improved the traditional Arnold transformation by adding two parameters a and b, furthermore it use Logistic map to generate the parameter sequences. The digital image is blocked, then carry out Arnold transformation with different parameters on each image block, after that put the transformed pixels on the corresponding position of the encrypted image, thus achieving image location scrambling. The results of simulation show that this algorithm can achieve good image encryption effect, and it has a large key space, key sensitivity. It basically meets the effectiveness and security requirements of image encryption. Cryptography is done in two ways: (i) symmetric (private) key cryptography, where only single key is used to do encryption and decryption, (ii) asymmetric (public) key cryptography, where one key is used to do encryption and other key is used to do decryption. In (4), the author proposed a method, SD-AEI, for image encryption, which is an upgraded module for SD-EI combined image encryption technique and basically has three stages: 1) In first stage, each pixel of image is converted to its equivalent eight bit binary number and in that eight bit number, the number of bits, which are equal to the length of password are rotated and then reversed; 2) In second stage, extended hill cipher technique is applied by using involutory matrix, which is generated by same password used in second stage of encryption to make it more secure; 3) In third stage, the whole image file is randomized multiple number of times using Modified MSA Randomization encryption technique and the randomization is dependent on an unique number, which is generated from the password provided for encryption. In (5) a novel scheme for optical information hiding (encryption) of two-dimensional images by combining image scrambling techniques in fractional Fourier domains is proposed. The image is initially random shifted using the jigsaw transform algorithm, and then a pixel scrambling technique based on the Arnold transform (ART) is applied. Then, the scrambled image is iteratively encrypted in the fractional Fourier domains using randomly chosen fractional orders. The parameters of the architecture, including the jigsaw permutations indices, Arnold frequencies, and fractional Fourier orders, form a huge key space enhancing the security level of the proposed encryption system. Optical implementations are discussed and numerical simulation results are presented to demonstrate the flexibility and robustness of the method (6) gives an Enhancement to Image security in which Data bits from textual message are encrypted through key to some suitable nonlinear pixel and bit positions about the entire image. As a result, a watermarked image is produced. After that three different image shares using any two components of R, G and B of entire watermarked image are formed. The key is also divided into three different logical blocks by digits. By combining any two blocks of key, key shares are formed and are assigned to image shares. Out of those three shares, only addition of any two is able to make the full image or key. At the I