Modified BCH data hiding scheme for JPEG steganography

In this article, a new Bose-Chaudhuri-Hochquenghem (BCH)-based data hiding scheme for JPEG steganography is presented. Traditional data hiding approaches hide data into each block, where all the blocks are not overlapping each other. However, in the proposed method, two consecutive blocks can be overlapped to form a combined block which is larger than a single block, but smaller than two consecutive nonoverlapping blocks in size. In order to embed more amounts of data into the combined block than a single block, the BCH-based data hiding scheme has to be redesigned. In this article, we propose a way to get a joint solution for hiding data into two blocks with intersected coefficients such that any modification of the intersected area does not affect the data hiding process into both blocks. Due to hiding more amounts of data into the intersected area, embedding capacity is increased. On the other hand, the nonzero DCT coefficient stream is modified to achieve better steganalysis and to reduce the distortion impact after data hiding. This approach carefully inserts or removes 1 or -1 coefficients into or from the DCT coefficient stream according to the rule proposed in this article. Experimental results show that the proposed algorithms work well and their performance is significant.