Two Level Image Encryption using Pseudo Random Number Generators

The escalating significance of securing data over the network has encouraged development of secure encryption algorithms. Cryptography is a technique that assists in development of such secure algorithms. It involves converting intelligible data into an unintelligible form to protect it from intruders. In this paper, the authors propose a simple and secure process to secure images. The image encryption process makes use of two Pseudo Random Number generators. In the first step, Linear Feedback Shift Register algorithm is used to swap the rows of the original image. This is followed by the swapping of the columns to produce an intermediary cipher image. In the second step, Blum Blum Shub algorithm is used to substitute the intensity of each pixel of the intermediary cipher image, to produce the final encrypted image. Various analysis tests are then performed to check the quality of the encrypted image. The test results prove the efficiency of the proposed image encryption process.