5G-AKA

Technical Explanation

5G-AKA is an enhanced version of EPS-AKA. It provides mutual authentication: the network proves its authenticity to the device (via AUTN), and the device proves its authenticity to the network (via RES*). In 5G-AKA, the serving network (AMF) receives a hashed response (HXRES*) to verify that the UE is attempting authentication, while final verification of the full RES* is performed by the home network (AUSF). This prevents serving networks from fabricating authentication successes.

Key Functions

• Cryptographic mutual verification of UE identity and Home Network validity
• Derivation of 256-bit anchor master key K_SEAF in Home AUSF
• Serving network isolation preventing rogue visiting networks from spoofing UE profiles
• Support for non-3GPP access authentication via EAP-AKA'