Abstract: “The incredible evolution of Internet technologies and its applications requires high level of security for data over the unsecured communication channel. Digital image steganography is technique for hiding information into a cover image. Least Significant-Bit (LSB) based approach is popular steganographic technique in spatial domain due to its simplicity and robustness. All the existing methods of steganography focuson embedding mechanism with less consideration to the pre-processing, such as encryption of secrete image. The conventional steganographic model does not provide the preprocessing, needed in image basedsteganography for better security. The proposed work presents a unique technique for Image steganography based on the S- Box mapping. The preprocessing of secrete image is carried by shuffling of secrete image blocks using three 4×4 unique S-boxes. The preprocessing provide high level of security as extraction is not possible without the knowledge of mapping rules of Substitu”

Keywords: Steganography, S-Box mapping , LSB Technique, Cryptography, Preprocessing of Secrete Image.