2018-10-17

Steganography is the science of hiding a confidential message into a cover media without any perceptual distortion of the cover media. Using steganography, information can be hidden in the carrier items such as images, videos, sounds files, text files, and Deoxyribonucleic Acid (DNA) while performing data transmission. In DNA steganography field, it is a major concern of the researchers how to improve the security of hiding scheme without affecting the capacity, payload, and Bit Per Nucleotide (BPN). In this work, a proposed modified scheme for data hiding within DNA sequences is presented. This is represented in the proposed Modified Table Lookup Substitution Method (MTLSM), where the original TLSM using the location sets for hiding confidential message bits, and these location sets must be sent through a secure channel before performing data transmission. So, the proposed scheme replaces the location sets with an 8-bit binary coding rule which makes the security more stable than the original one. To provide a double layer of security, a proposed Modified ElGamal Cryptosystem (MEC) is proposed and combined with MTLSM. A proposed MEC speeds up the execution time and reduces the expansion rate in the file size after the encryption process takes place. The security of the proposed MEC is the same as the original ElGamal cryptosystem, which is based on the difficulty of solving the discrete logarithm problem. The results and comparisons have proven the ability of the proposed scheme in balancing among the three critical properties for any DNA steganography scheme: capacity, payload, and BPN.