Authentication: 5G-AKA detailed procedure

Mutual Authentication in 5G

5G-AKA provides mutual authentication — both the UE and network verify each other's identity. The process starts when the AMF sends the UE's SUCI to the AUSF, which forwards it to the UDM. The SIDF in UDM decrypts SUCI to reveal the SUPI, and the ARPF generates an authentication vector using the permanent key K. The vector includes RAND (random challenge), AUTN (authentication token for network verification), XRES* (expected response), and KAUSF (the anchor key for key derivation).