A hybrid encryption scheme of DNA and chaotic precoding for IMDD-FBMC systems

A new scheme that combines deoxyribonucleic acid (DNA) encryption algorithm and chaotic Walsh-Hadamard transform (WHT)/discrete Fourier transform (DFT) precoding to improve security performance is proposed for the first time in the filter bank multicarrier (FBMC) systems with intensity modulation and direct detection (IMDD). In our proposed scheme, we employed DNA and chaotic WHT/DFT precoding to achieve bit-level and symbol-level encryptions, respectively. With this hybrid encryption scheme, it is expected not only to enhance data transmission security but also to improve the bit error rate (BER) performance. We conducted experiments in the 16/32 quadrature amplitude modulation (QAM)-FBMC systems with IMDD. The relevant results show that our proposed scheme can improve receiver sensitivity by around 1 dB at the BER of 3.8e-3 compared with the scheme using only DNA encryption or without encryption. And a huge key space of 101806/101024 by DNA-chaotic WHT/DFT encryption is achieved. In addition, the net bit rate of transmission systems can be enhanced with a similar BER performance, compared to the optical orthogonal frequency division multiplexing (OFDM) systems.