Adaptive Secure Communications With Key Updating Using 4-D Hyper-Chaos in Digital Mobile Fronthaul

In this letter, an integration scheme of adaptive secure communications and key updating based on incremental delta sigma modulation (DSM) and 4D chaotic system is proposed, improving the security and tidal effect robustness in digital mobile fronthaul. The session key derives from the in-band noise (IBN) of DSM. 4D chaotic system prevents the leakage of transmission bit and session key. By adjusting oversampling ratio, the proposed scheme achieves adaptive error-free performance in the experiment, reaching a maximum transmission bit rate of 12.799 Gbit/s and key updating rate of 2.133 Gbit/s. We analyze the IBN property in terms of time and frequency domains. Further, the session key of 10 Gbits is proven to pass the randomness test. The key space with 10135can resist brute force attacks for plaintext and session keys.