NORA-AKA: Novel Open-RAN-Enabled Local Authentication and Key Agreement Protocol for 5G Networks

Evolution of mobile networks, has introduced significant challenges in managing secure, scalable, and efficient user authentication, especially in the context of massive IoT deployments and ultra-dense heterogeneous networks. Traditional authentication protocols, such as 5G-AKA and Extensible Authentication protocol (EAP-AKA), rely heavily on centralized core components like the Access and Mobility Management Function (AMF) and the Authentication Server Function (AUSF), which creates performance bottlenecks and introduces latency, particularly during high-volume access and frequent handovers. To address these limitations, this paper proposes a Novel Open-RAN-Based Authentication and Key Agreement protocol (NORA-AKA) tailored for 5G networks. Unlike centralized schemes, NORA-AKA supports local authentication by leveraging Open-RAN principles and deploying a dedicated lightweight module, the NORA-Box, within the radio access network. This approach enables the Serving Network (SN) and Home Network (HN) functions to be executed locally, thereby reducing core network congestion and improving response time. The proposed scheme incorporates two types of authentication mechanisms to support both initial access and handover scenarios, ensuring resilience to replay attacks, impersonation, and service denial. It adheres to 3GPP TS 33.501 standards while introducing a distributed identity management paradigm suitable for dynamic 5G environments. Performance and security evaluations indicate that NORA-AKA reduces communication overhead and authentication delay relative to conventional 5G-AKA under the considered analytical and experimental settings, while improving robustness against mobility-related threats. These results suggest that NORA-AKA is a promising approach for localized authentication in Open-RAN-enabled 5G environments and beyond.