Multi-dimensional disturbance secure communication system with dynamic key hiding transmission based on power-domain non-orthogonal multiple access

Abstract

Data security is becoming more critical in networks as high-speed and large-capacity optical transmission becomes more common. Cryptographic protocols at the MAC layer and higher tiers of the protocol stack are under threat as a result of quantum computer developments. Optical physical layer encryption has great advantages in optical communication security transmission, which can be compatible with a variety of networks, and achieve an efficient and secured ultra-high high-speed data transmission. In this work, we propose a physical layer encryption scheme based on orthogonal frequency division multiplexing power-domain non-orthogonal multiple access (OFDM-PD-NOMA) technique for the dynamic key hiding transmission and multi-dimensional disturbance. The encryption scheme realizes multi-point mutual-coupling key transmission and multi-dimensional disturbance encryption by a 3D discrete chaotic model. The encrypted data and the dynamic key are transmitted together by multichannel signals in PD-NOMA, then, the chaotic signal generated by chaotic generator is used to mask the dynamic key. 3D chaotic sequences generated by the dynamic key are used to encrypt bits, symbols and carriers of the original signal. The initial key, the dynamic key and the chaotic signal realize multi-point mutual-coupling. We conduct a 74.6 Gb/s encrypted quadrature phase shift keying (QPSK)-OFDM-PD-NOMA signal transmission over 2 km 7 core fiber. The key space of encrypted scheme can reach 10462. Finally, experimental results show that the original data can be recovered accurately, and the bit error rate (BER) of the dynamic key is close to zero. The security and reliability of the system have been verified, and this scheme has an important application prospect in the future optical communication system.