Abstract:
In a world of digital technology, maintaining the security of the secret data has become a big challenge. One way to achieve this is to encrypt the message before it is sent. But encryption draws the attention of third parties, which may cause the third party to seek breaking the encryption and detecting the original message. Another way is steganography, steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message. In this thesis a concept for performing hidden secret data, called secure audio Steganography using modified Least Significant Bit (LSB) and Discrete Cosine Transform (DCT), was presented. Which is consist of two stenographic methods utilized respectively. Two-levels of stenography have been applied; the first level is called (the lower-level), and it has been applied using DCT. In this level three different plain texts are used as a secret data, and the cover is gray scale image, the output from the first level is a stego image. The second level is called (the Upper-level); it has been applied using modified Least Significant Bit. In this level Wav file has been used as a cover media and embeds (the gray scale image output from the first level) as a secret data.
After implementation of the proposed method, many experiments have been conducted. Different sizes of plain texts and different sizes of cover have been experimented. Finally comparative analysis had been applied to experiments results and illustration to strengthand weakness points of proposed system against existing systems is obtained.
