A.4 K_AF derivation function

33.5353GPPAuthentication and Key Management for Applications (AKMA) based on 3GPP credentials in the 5G System (5GS)Release 17TS

When deriving a K_AF from K_AKMA, the following parameters shall be used to form the input S to the KDF:

– FC = 0x82;

– P0 =AF_ID;

– L0 = length of AF_ID

The input key KEY shall be K_AKMA.

AF_ID is constructed as follows:

AF_ID = FQDN of the AF || Ua* security protocol identifier, where the Ua* security protocol identifier is specified as Ua security protocol identifier in Annex H of TS 33.220 [4].

Annex B (normative):
AKMA profiles for Ua* protocols