A novel image encryption method to reduce decryption execution time in cloud

Parallel computing on cloud infrastructure had gained tremendous attention and popularity in recent years. In this paper, we propose a new technique to encrypt an image for secure image transmission and parallel decryption using cloud resources. The encoding of the image is done using the FFT conjugate complex property and private random phase key value shared between sender and receiver. First, using FFT complex conjugate property, we construct a two dimensional matrix consisting of real and imaginary portion of the image. Second, we encrypt the complex conjugate matrix using private random phase key value shared between sender and receiver. Detailed simulations have been carried out to test the encryption algorithm. Furthermore, we use cloud resources for the development of an efficient parallel image encryption and decryption algorithm. Significant speedup was achieved using different image size and number of cloud servers.