Inter-Network Function Authentication

In the 5G Service-Based Architecture, every Network Function authenticates to every other NF using mutual TLS at the transport layer plus OAuth2 access tokens at the application layer. The NRF acts as the authorisation server and issues short-lived JWT tokens scoped to the requested service, NF type, and PLMN. This combination prevents any compromised or rogue NF from invoking arbitrary services and replaces the implicit trust model that plagued earlier mobile generations.

Categories: Radio Access NetworkCore NetworkSecurity Controls

Inter-Network Function Authentication in context

The radio access network is where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations and downgrade attacks; defenses rest on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

To place Inter-Network Function Authentication in the wider telecom-security picture, review Cipher, HTTP, OAuth2 in 5G Core, SMPP, NRF Poisoning and 1G — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.