الفهرس 
Chapter 1: General IntroductionOnly 14 pages are availabe for public view
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Abstract
Due to the open communication channels having greater vulnerability to security threats causing unauthorized information access, securing the data during its transition in public domain channels (i.e. internet) becomes more important nowadays. Encryption and steganography are the common methods to secure communications. Steganography has been widely used in the recent historical times and the present day. It can be defined as the study of invisible communication that usually deals with the ways of hiding the existence of the communicated message. It is used to hide the message into a host file without any perceptual distortion of the host file. By using steganography, information can be hidden in different carriers such as video files, audio files, text files or images and then transmitted secretly to the receiver. br In this thesis, a new image steganography system has been proposed, which have good PSNR, MSE and capacity. This system contains two proposed method, which will be explained, discussed and evaluated in the following chapters of this thesis. br The first proposed method is New Image Steganography Method Using Zero -#111;-#114;-#100;-#101;-#114; Hold Zooming (ZOH). In this method, we proposed a new technique of embedding a secret message into the cover image. In this method the pixel of the image is modify if the end of the average of two adjacent pixels are not equal to the bit of the message, But the pixel of the image doesn’t change if the end of the average is equal to the bit of the message. In extraction, the image will be zoomed using ZOH method calculate the average between two adjacent elements -#102;-#114;-#111;-#109; the rows respectively, and place their result in between those two elements. First do this row wise and then do this column wise then extract the pixel -#102;-#114;-#111;-#109; the image as show in extraction algorithm and save it. The results showed that the proposed method gives better results of higher PSNR lower MSE. br The second proposed method is called ZOH-Braille, in this method; we modify the secret message that embedded into the cover not the technique of embedding of the previously proposed image steganography method using Zero -#111;-#114;-#100;-#101;-#114; Hold zooming (ZOH) by using LSBraille (Braille method of reading and writing for blind people) method.