Segment index encryption scheme based on the memristor for W-band wireless reflective communication

To ensure the physical layer security of W-band wireless communication systems and expand the scope of application, this paper proposes a segment index encryption scheme based on the memristor for W-band wireless reflective communication. Utilizing a memristor, a nonlinear three-dimensional hyperchaotic model is constructed to enhance the nonlinear dynamics of the chaotic system. The chaotic sequences generated by the chaotic model are used for segment initial position indexing, determining length, XOR encryption, and scrambling to produce the ciphertext. The receiver optimizes the bit error rate (BER) of the key using a decision-making approach. This paper experimentally verifies the feasibility of W-band wireless encrypted signals over a 10 m straight transmission and reflective transmission. The system performs optimally when the power distribution ratio (PDR) is 4, the minimum BER of straight transmission is 2.23 × 10^-6, and the minimum BER of reflective transmission is 8.47 × 10^-6. Compared to unencrypted signals, the encrypted signal achieves a maximum input optical power (IOP) increase of 0.4 dB in straight transmission and 0.7 dB in reflective transmission, with a sensitivity of E-15 and a key space of up to 10⁹³. The maximum difference in IOP between the two transmission methods is 4.5 dBm. Under the hard decision forward-error correction (HD-FEC) threshold @ 3.8 × 10^-3 the transmission rate of straight encrypted signals can reach 30 Gb/s, while reflective encrypted signals can reach 20 Gb/s. The experimental results indicate that this scheme can securely transmit reflective encrypted signals and demonstrate its robustness against potential eavesdropping and interference. It provides a reliable solution for maintaining data integrity in challenging environments such as urban pipeline communication, wireless communication within buildings, intelligent transportation infrastructure development, and other fields.