Convergence of compressed sensing encryption and deep network recovery in RoF system

In this paper, a security scheme based on the convergence of compressed sensing (CS) encryption and deep network recovery is proposed in radio-over-fiber (RoF) system. In this scheme, CS encryption and deep network recovery are performed at the transmitter and receiver respectively. At the transmitter, the original data are selected based on the compression ratio (CR) and then protected by a three-stage encryption process after CS compression, and the dynamic key (DK) is generated from the original data. In the encryption process, the compressed information is scrambled by 3D rotation, then singular value decomposition (SVD) and DK embedding is implemented, followed by constellation symbol masking. At the receiver, a deep network is used to recover the original data and improve recovery performance. The proposed scheme is experimentally demonstrated and the encrypted OFDM signals are successfully transmitted over 50 km standard single-mode fiber (SSMF) and 5 m wireless channel. The experimental results show that the scheme has a key space of 1.34 x 10233, which can resist brute intrusion by eavesdroppers, and the bit error rate (BER) is below 10-3 when the received optical power (ROP) is greater than 4 dBm. Additionally, the mean structural similarity (MSSIM) is higher than 0.97, which provides a gain of 0.2 compared to traditional methods. So, the proposed scheme has good security performance and recovery performance, which has a significant potential for application in future optical networks.