High Embedding Capacity Data Hiding Technique Based on EMSD and LSB Substitution Algorithms

Data hiding called steganography is a security technique to protect secret data throughout the transmission from malicious attackers. The purposes of steganography are to obtain good stego-image quality, high embedding-capacity, low computational complexity, visual imperceptibility, undetectability, and more security. In this paper, we offer a new hybrid image steganography technique based on least significant bit (LSB) substitution and enhanced modified signed digit (EMSD) algorithms. The proposed algorithm utilizes n adjacent cover image pixels to hide the secret data with EMSD algorithm, and least significant k-bit for LSB substitution algorithm. Hence, it has more embedding capacity than the EMSD algorithm and exploiting modification direction (EMD) based algorithms. We obtain that the stego-image quality is better than 43 dB when the payload is 2.404 bpp. The results of experiment represent that this algorithm ensures high embedding-capacity while preserving acceptable visual stego image quality that can be undetectable by human eyes. Also, the hybrid of the EMSD and LSB substitution algorithms is to difficult for malicious people to consolidate data by scrambling secret data bits.