A coding and substitution frame based on hyper-chaotic systems for secure communication

Secure communication has always been important ever since ancient times. Both encryption and steganography are effective ways for secure communication. Inspired by the central dogma that regulates the transfer of genetic information in molecular biology, this paper introduces a coding and substitution frame for both encryption and steganography. The frame consists of three parts: the construction of the pseudo-codon table, the encoding of the original media and additional data, and the substitution. After the original media is encoded, it is substituted codon by codon according to the encoded additional data and a constructed pseudo-codon table. Hyper-chaotic systems have been used in the construction of the pseudo-codon table, the encoding of original media and additional data, and the substitution, all of which have offered more randomness and larger key space to the frame. To demonstrate the validity and efficiency of the frame, this paper offers the implementation of the frame in image encryption and in image steganography. The frame offers more security to steganography algorithms and better efficiency to encryption algorithms. Experiments and analysis demonstrate the excellent performances of the steganography and encryption schemes under the proposed frame.