DCT based robust coverless information hiding scheme with high capacity

For a considerable time, individuals have been searching for the most effective way to secretly transmit information, making it challenging for anyone without authorization to decode it. Steganography is a method that conceals confidential information from unauthorized users. The message is encrypted, allowing only the intended recipient to access the message. In the case of image steganography, the message is hidden within a cover image. One technique involves modifying the image, so the receiver can still decode the information, even though it is not visible to the human eye. However, statistical analysis can uncover concealed information, even if it is not noticeable. To counter this issue, researchers developed a technique called Coverless Information Steganography, which sends the recipient an image that already contains a hidden message, thus reducing the possibility of steganalysis. A novel technique based on the direct current (DC) coefficient of the cover image is discussed here, where a hash sequence is created by computing the DC coefficient of each 8×8 sub-block and then XORed with a secret message to form a bit sequence. The capacity and robustness of the method are evaluated to determine its efficiency compared to other implementation strategies.