An Image Encryption using Block based Transformation and Bit Rotation Technique

Along with the rapid increasing growth of computer and network technologies, images are being transmitted more and more frequently. Security of image is a big issue. Image information is lively and visual, and has been an important means of expressing information of person. There are many encryption algorithm had been available each one having some strength and weakness. In this paper we present an image encryption technique that combines the concept of block based transformation and pixel manipulation. The proposed method consist of two stages 1) In first step we apply block based matrix transformation for pixel position manipulation; 2) In second stage, apply bit rotation technique that change the value of each pixel.