Securing 5G Critical Interfaces: A Zero Trust Approach for Next-Generation Network Resilience

The dynamic and virtualized nature of 5G networks introduces unprecedented challenges in securing critical interfaces such as N1, N2, N3, and Service-Based Interfaces (SBIs). These interfaces are essential for interconnecting 5G components like the NG-RAN, 5GC, and external entities but are increasingly targeted by sophisticated cyberattacks. This paper explores a novel application of Zero Trust Architecture (ZTA) to strengthen the security of these critical interfaces. By analyzing vulnerabilities across traditional, centralized, and virtualized RAN implementations, the study identifies key threats and highlights the gaps in existing security frameworks. It further proposes an adaptive ZTA framework tailored for 5G environments, emphasizing continuous verification, granular access control, and cross-layer security. The findings offer actionable insights into integrating ZTA principles within 5G networks, paving the way for a unified, scalable, and resilient security paradigm.