Steganography is the art of hiding data inside a carrier file in such a way that an intruder or unwanted personnel is unable to detect the presence of data inside the carrier file. Audio, Video and Images are the different possible carrier files that can be used. This paper describes a steganographic technique which makes use of an image file as a carrier to hold the secret message and transfer it over the communication medium. There are two popular schemes used for image steganography: spatial domain embedding and transform domain embedding. Most of the steganographic techniques discussed in literature either use spatial domain or transform domain to embed the secret message. Here we have proposed a novel steganographic technique that combines both the spatial domain as well as the transform domain approach to achieve greater security. We have chosen LSB substitution technique for spatial domain embedding and Discrete Wavelet Transform (DWT) for transform domain embedding. The paper also proposes technique to combine cryptography with the proposed image steganography technique. Here we make use of the S-DES also known as the simplified DES algorithm for encryption. Our experimental results show that the proposed steganographic technique achieves moderate embedding capacity with high level of security.

Steganography S-DES DWT Discrete Wavelet Transform Carrier Image Stego File Stego Image Brightness attack Cropping attack