Abstract
Steganography is the art and science of hiding communications. In contrast to cryptography, which aimed at encrypting messages such that it is infeasible to an attacker to decrypt the messages, Steganography aimed at hiding the presence of communication in a medium that is used to carry secret messages (image, audio, or video). This has to look innocuous to an attacker, so it will not raise suspicion from an eavesdropper. Most steganographic systems can be attacked visually or statistically (steganalysis). Systems that are resistant to such attacks, provides a relatively small capacity for steganographic messages. In this paper, a new technique is introduced to hide data in the least significant bit (LSB) of the discrete cosine transform (DCT) coefficients of JPEG image blocks. This technique exploits the ratio of even to odd coefficients in each image block and embeds data bits in a way that preserves the ratio between even and odd DCT coefficients of each image block. A Block Based Steganography (BBS) algorithm offers high capacity with statistically minimal changes compared to current steganographic algorithms. A comparison between BBS algorithm and current steganographic systems will be introduced. [PUBLICATION ABSTRACT]