High Secure Image Steganography in BCBS Using DCT and Fractal Compression

We propose a new approach to steganography for hiding secret images in the digital media. Steganography differs from digital watermarking because both the information and the very existence of the information are hidden. We refer it as Blind Consistency based Steganography, which provides high imperceptibility and security for information from subterfuge attack. The Existing Steganographic approaches are unable to handle the Subterfuge attack i.e, they cannot deal with the opponents not only detects a message, but also render it useless, or even worse, modify it to opponent favor. The advantage of BCBS is the decoding can be operated without access to the cover image and it also detects if the message has been tampered without using any extra error correction. To improve the imperceptibility of the BCBS, DCT is used in combination to transfer stego-image from spatial domain to the frequency domain. The hiding capacity of the information is improved by introducing Fractal Compression and the security is enhanced using by encrypting stego-image using DES. Finally the Embedding and Extraction process are detailed in the paper, along with the analysis on capacity, security and imperceptibility. The experimental results are provided as well.