A Novel Approach for Multilevel Steganography

The proposed scheme is a multi level steganography in which steganography is done at two places. The cover image is divided into fixed size blocks and then Discrete Cosine Transformation is applied into each block of cover image. The resulting DCT coefficients are quantized using quantization process. In the quantized DCT coefficient, the encrypted data file is embedded by using Least Significant bit technique. The resultant stego image is encrypted by Hill cipher algorithm. The encrypted image is hiding into another image. In the second level steganography the cover image is divided into equal sized blocks and then Discrete Wavelet Transformation is applied on each block. In the DWT coefficients the encrypted image is hidden by applying Least significant bit technique. Finally the performance parameters are evaluated. Keywords— Steganography, DCT, DWT, Quantization, Huffman coding, AES Rijndael, Hill Cipher Algorithm