Implementation of an Advanced Image Steganography Technique Using Modified Data Image

Abstract

The science of secret communication is known as steganography. Steganography is a Greek word, which means covered writing. Steganography hides the secret data from unauthorized user. Unlike cryptography, steganography hides the existence of secret information rather than hiding its meaning only. Many different file formats can be use as cover media but these days the digital image based steganography is most popular on internet and web. The capacity of hiding secret data is limited in steganography and it depends on size of the cover image. There is a tradeoff between the stgo image quality and the capacity of steganography. Therefore, the quality of stego image and capacity of steganography are still a challenging field and this is the goal of proposed method. In this thesis, a new image steganography technique has been proposed. In this technique the secret data is change into a new format. The new data cannot be decoded without knowing the actual algorithm. In this new data, there is less counts of number of ‘1’ compare to original data, due to this mostly the stego image’s pixel value follows the cover image pixels value after using the XORing method between the cover image and the secret data. In this thesis, Lenna image has been used as reference image and after applying this method, the count of number of ‘1’ has been reduced by 20%(nearly) compare to the original data. By using proposed method, not only the security of secret data increases but also it increases the quality of the stego image. The result shows that the proposed method improved the value of PSNR and MSE of the stego image and it fulfills all the aspects of image steganography. In this thesis, various data images and various cover images have been analyzed.