AUSF

Technical Explanation

The AUSF is the security authentication authority in the 5G Core. During UE initial registration, the AMF forwards the authentication request to the AUSF. The AUSF retrieves authentication credentials from the UDM, generates authentication challenges (RAND, AUTN, HXRES*), validates the UE's response (RES*), confirms successful authentication, and derives the intermediate master security key (KSEAF) which is passed to the AMF to derive KAMF and ciphering keys.

Key Functions

• Execution of 5G-AKA and EAP-AKA' authentication procedures
• Validation of UE authentication responses against UDM vectors
• Derivation of master anchor security keys (KSEAF)
• Enforcement of 5G subscriber identity confidentiality and anti-spoofing