Multi-Domain Multi-Level Optical Encryption Transmission Scheme Based on Memristor Rulkov Neuron Chaos

This paper proposes a multi-domain multi-level (MDML) orthogonal frequency division multiplexing (OFDM) optical encryption transmission scheme based on memristor Rulkov neuron chaos. In this scheme, the masking factors generated by the memristor Rulkov neuron chaos are used to encrypt the information of the digital modulation process, so as to improve the anti-malicious attack performance of the system. Among them, the memristor unit constructs a simple discrete map to capture the complex nonlinear neuronal behavior, and the generated masking factors encrypt the data in the digital modulation process. In addition, the proposed scheme introduces the encryption depth control parameters (EDCP), which can make up for the information damage caused by the complexity of encryption. The selection of EDCP can not only encrypt the data, but also change the distribution of the uniformly distributed constellation points position, reduce the average power of the constellation points, and improve the transmission performance of the fiber communication system. A 9.41 Gb/s OFDM signal transmission over 25 km standard single-mode fiber (SSMF) is experimentally demonstrated. The introduction of memristor Rulkov neurons makes the key space reach 10¹¹⁶. The introduction of the EDCP makes the key space expand 10³⁶ times. When the bit error rate (BER) is 10⁻², the receiving sensitivity of the EDCP with 0.2, 0.4, 0.8 is 6 dB higher than that of the EDCP with 0.9, 0.3, 0.1. The results show that the encryption scheme can effectively resist illegal attacks and improve the security performance of the system.