A NEW STENOGRAPHY TECHNIQUES USING HUFFMAN CODING & HAMMING CODE

Abstract

In Steganography, the total message will be invisible into a cover media such as text, audio, video, and image in which attackers don’t have any idea about the original message that the media contain and which algorithm use to embed or extract it. In this thesis, the proposed technique has focused on Bitmap image as it is uncompressed and convenient than any other image format to implement LSB Steganography method. For better security symmetry key cryptography technique has also been used in the proposed method. Before applying the Steganography technique, Symmetry key cryptography will change the secret message into cipher text to ensure two layer security of the message. In the proposed technique, a new Steganography technique is being developed to hide large data in Bitmap image using filtering based algorithm. This algorithm first compresses the data, so, big amount of data is embed in small space, and on that code word, Hamming Encoding is also applied. If there is any change in the pixels of image due to noise, hamming encoding will help us to recover the message. This algorithm uses MSB bits for filtering purpose. This method uses the concept of status checking for insertion and retrieval of message. This method is an improvement of Least Significant Bit (LSB) method for hiding information in images. It is being predicted that the proposed method will able to hide large data in a single image retaining the advantages and discarding the disadvantages of the traditional LSB method. Various sizes of data are stored inside the images and the PSNR are also calculated for each of the images tested. Based on the PSNR value, the Stego image has higher PSNR value as compared to other method. Hence the proposed Steganography technique is very efficient to hide the secret information inside an image.