Semantic Secrecy Assessment of Physical Layer Security in 5G NR Uplink Transmissions Under Fading Channel Conditions

This paper proposes a system architecture that embeds semantically-secure information-theoretic physical layer security (IT-PLS) non-intrusively into a 5G New Radio (NR) system in order to protect uplink transmissions via physical uplink control channels (PUCCH) against post-quantum eaves-dropping attacks. We implement a proof of concept of such system employing a code construction based on a modular coding scheme with a universal hash function that ensures semantic secrecy. We conduct link-level simulations of wiretap channels under different frequency-selective fading conditions and noise characteristics in order to evaluate the performance of such implementation for slow and fast fading scenarios. We model them using tapped delay line channel models involving rural and urban scenarios with line-of-sight (LOS) and non-LOS radio conditions, as specified by the 3GPP TR 38.901. We characterize such system by measuring the distinguishing error rate, block error rate, and secrecy outage probability under different time-varying fading channels. Our case study outlines how IT-PLS can be transparently embedded into future 6G systems as well.