STUDY OF STEGANOGRAPHY TECHNIQUES

Abstract

The rapid development in both computer technologies and internet made the security of information one of the most important factors of information technology and communication. Steganography has emerged as a powerful and efficient tool which provides a high level for security. Steganography is an area of information security that aims to hide a secret message within a carrier. The term steganography comes from the Greek words stegano (cover) and graphy (write). As result a steganography literally means covered writing. Depending on the media in which we hide the data, Steganography is classified as text, image, audio, video or protocol. In this thesis, we apply a steganography algorithm that uses the motion vectors as a carrier to embed the secret information. From the results we conclude that the higher the threshold the lower degradation is obtained, also we found that the embedding capacity is inversely proportional to the threshold. By increasing threshold the number of selected frames for the embedding process increase but this depends on the dataset itself. We found that at constant threshold, the less the number of the selected blocks, the large the number of frames needed for the embedding process, the quality of the stego frame increases and low degradation is obtained. Also we present a proposed video steganography algorithm in the frequency domain. It was applied to two datasets to study the effect of selecting red, green and blue band on the quality of stego frames. From the results we found, the quality of the stego frames after data embedding into red channel, green channel and blue channel depends on the nature of the dataset (the frequency values of pixels).