A New Approach for Image Encryption in the Modified RSA Cryptosystem Using MATLAB
The need of making important information that is being exchanged between participants through unsecure websites has intersted cryptoligists to create and modify some secure cryptosytems to prevent these information from getting hacked or cracked.In this paper, a particular strategy in thepublic key cryptosystem called RSA Cryptosystem is presented to be applied over gray and color images with the help of MATLAB Program. Since the RSA cryptosystem is a well known secure cryptosystem, we use MATLAB to apply this cryptosystem over gray and color images. Moreover, that would be generating two algorithms for the encryption and decryption procedures. These algorithms can be applied over the plain image and cipher image after reading them in the matrices forms. However, the image is partitioned into blocks that are n x m matrices. Since the RSA cryptosystem is a secure public key cryptosystem since its security based on the difficulty of the factoring problem, which is factoring a positive integer R into a product of two primes, we apply this cryptosystem over images using MATLAB with increasing the number of the primes in R. This gives the modified RSA cryptosystem has a higher security than the RSA cryptosystem, because decrypting any encrypted images requires factoring the large integer composed of the product of many large primes, and it requires knowing the size of the blocks that are formed from plain matrix. Therefore, this approach of encrypting and decrypting images using RSA cryptosystem with some modifications more immune against any attacks in the transmission of images in all agencies in the era of the information technology.