A steganographic system for embedding image and encrypted text

Abstract

Need for secured communication and reduced memory usage are the major issues in recent times. These issues have led to the development of many steganographic algorithms. This paper undertakes the study and implementation of steganographic system with prime concern of secured communication of images along with associated text. An image steganographic model proposed by N satisha et al., [1] is modified in such a way that a confidential image is embedded along with the secret text encrypted into single cover image. Text embedding along with the image is carried out by decomposing the cover image and embedding text in one of the segments. Text data is embedded in Spatial domain using Least Significant Bit Substitution(LSB) Technique yielding one stego segment. Since spatial domain techniques are more prone to attacks, text data is encrypted using Advanced Encryption Standard(AES) algorithm for better security. Payload image is embedded into other segment, where Lifting Wavelet Transform(LWT) and Dual Tree Complex Wavelet Transform(DTCWT) is applied to payload image and other segment of cover image respectively. Image embedding process is carried out by coefficient replacement and adaptive scaling technique, there by other stego segment is obtained. Stego image is obtained by merging the stego segments. It is observed that, even after embedding both text and image, the same level of robustness and security is maintained with good PSNR and Correlation Coefficient values, thereby assuring the compact storage feature.