Image Encrption and Decription in Matlab

In the past decade, image encryption is given much attention in research of information security and a lot of image encryption algorithms have been introduced. Due to some intrinsic features of images like bulk data capacity and high data redundancy, the encryption of image is different from that of text; therefore it is difficult to handle them by traditional encryption methods. In the proposed work, a new image encryption algorithm based on Magic Rectangle (MR) is being applied. To begin with, the plain-image is converted into blocks of single bytes and then the block is replaced as the value of MR. Further, the control parameters of Magic Rectangle (MR) are selected randomly by the user. Subsequently the image is being encrypted with public key cryptography algorithms such as RSA, ElGamal etc. The experimental result shows that the proposed algorithm can successfully encrypt/decrypt the images with separate secret keys, and the algorithm has good encryption effect. Cipher text developed by this method will be entirely different when compared to the original image file and will be suitable for the secured transmission over the internet. Thus, this model provides an additional level of security to public key algorithm and efficient utilization of memory.