Physical Layer Security for 6G: Toward Achieving Intelligent Native Security at Layer-1

This paper lays the foundations for Physical Layer Security (PLS) as a native 6G communication operation mode. 6G mobile network will enable intelligent applications, automated services, and low-latency connectivity to data networks. Security performance improvements become vital as 6G ubiquitously integrates with critical infrastructure. This paper presents 6G PLS frameworks that combine a Deep Neural Network (DNN) with a shared key-based PLS scheme at the decoding stage to achieve higher security performance. The paper analyzes and models an Artificial Intelligence (AI)/Machine Learning (ML) PLS Layer-1 security detection scheme that achieves an impressive approximately
$10-15$
dB of improvement in Signal to Noise Ratio (SNR) performance over the linear PLS detection model in multiple fading environments modelled in COST 259 channel model and accompanying AWGN noise prior to error correction coding (ECC). An analysis of raw BER versus SNR is presented for multiple MIMO antenna sizes and codebook modulation orders. An analysis of the scheme shows that eavesdroppers cannot perfectly decode the secret information even under significantly improved SNR case scenarios. In contrast, legitimate receivers achieve nearly perfect secrecy at lower SNR cases by adopting the ML-based PLS model. In addition, the paper develops the theory and analysis, for the first time to our knowledge, of Alamouti Space-Time Coding (STC) over adjacent periods within a shared key-based PLS scheme with 2M transmit and 2M receive antennas. New modes of STC-based PLS show vast gains of approximately 15 dB over existing linear shared key-based PLS for multi-codebook modulation order in COST 259 environments and noise. Finally, the paper also proposes an operational overview of AI/ML integrated PLS with shared key-agreement protocol in an Open Radio Access Network (O-RAN) architecture model. The paper illustrates a secure, low latency, Layer-1 security O-RAN architecture scheme for 6G communication based upon “security Apps” for latency mitigation.