AUSF: Authentication Server Function

AUSF — The Authentication Authority

The Authentication Server Function handles all UE authentication in the 5G core. It supports two primary methods: 5G-AKA for authentication over 3GPP access and EAP-AKA prime for authentication over non-3GPP access such as WiFi. When a UE attempts to register, the AMF sends an authentication request to the AUSF over the N12 interface. The AUSF requests authentication vectors from the UDM over N13, constructs the authentication challenge, and sends it back to the AMF for relay to the UE. After verifying the UE response, the AUSF confirms authentication success and provides the anchor key.