Comparative and Evolutionary Analysis of Encryption and Physical Layer Security in 5G and 6G

Abstract

The evolution from 5G to 6G wireless networks is driving a fundamental transformation in encryption technologies. While 5G networks primarily rely on advanced classical cryptography, including AES, ECC, and RSA, emerging applications such as IoT, e-healthcare, and ultra-reliable low-latency communications demand lightweight, hybrid, and context-aware security schemes. The advent of quantum computing poses significant threats to classical cryptosystems, motivating the integration of quantum-resistant security techniques, including post-quantum cryptography (PQC), quantum key distribution (QKD), and physical layer security (PLS) in 6G networks. This review synthesizes recent research on classical, hybrid, and quantum-resistant security techniques, highlighting the shift toward multi-layered and adaptive security frameworks. A comparative analysis of PLS in 5G and 6G illustrates its transition from a complementary role to a core security mechanism, especially in ultra-low-latency, massive connectivity, and heterogeneous environments. Finally, open research questions and standardization challenges are discussed, emphasizing the need for scalable, energy-efficient, and interoperable security solutions for next-generation wireless networks.