Embedded FPGA Design for Optimal Pixel Adjustment Process of Image Steganography

We propose a prototype of field programmable gate array (FPGA) implementation for optimal pixel adjustment process (OPAP) algorithm of image steganography. In the proposed scheme, the cover image and the secret message are transmitted from a personal computer (PC) to an FPGA board using RS232 interface for hardware processing. We firstly embed -bit secret message into each pixel of the cover image by the last-significant-bit (LSB) substitution method, followed by executing associated OPAP calculations to construct a stego pixel. After all pixels of the cover image have been embedded, a stego image is created and transmitted from FPGA back to the PC and stored in the PC. Moreover, we have extended the basic pixel-wise structure to a parallel structure which can fully use the hardware devices to speed up the embedding process and embed several bits of secret message at the same time. Through parallel mechanism of the hardware based design, the data hiding process can be completed in few clock cycles to produce steganography outcome. Experimental results show the effectiveness and correctness of the proposed scheme.