Secure the Core: A novel approach for secure and efficient communication in Service-Based Architectures and beyond 5G networks

Security in Service-Based Architectures (SBA) is often overlooked, as it is an optional feature within Public Land Mobile Networks (PLMN) and Non-Public Networks (NPNs). Nonetheless, one of the primary objectives of upcoming mobile networks is to establish secure communications using APIs, TLS authentication, and OAuth 2.0 authorization, even though these might be seen as heavy protocols involving numerous messages between Network Functions (NFs) and the Network Repository Function (NRF). This paper presents an innovative technique, compatible with current standards, for authenticating the consumer NF and performing the service request while reducing the authentication time by more than 30%. The proposed mechanism builds on the TLS session resumption mechanism (0-RTT resumption for TLS 1.3), resuming a previously established session to improve performance. It proposes employing the NRF as both an authentication server and a storage for TLS sessions with each NF, which are then delegated to consumers. Results show that the service discovery and service request times can be 20.25% and 47.63% faster respectively, demonstrating the clear enhancement to the performance of the security mechanisms in SBA and core networks. • Secure session delegation allows 0-RTT TLS in 5G core network communication. • NRF stores and delegates PSKs to enable session resumption across NFs. • TLS offloading reduces handshake latency and overhead in 5G SBA. • OAuth 2.0 authorization integrated with TLS PSK delegation by NRF. • Framework enhances SBA performance while maintaining 3GPP security compliance.