A.2 KAKMA derivation function
33.5353GPPAuthentication and Key Management for Applications (AKMA) based on 3GPP credentials in the 5G System (5GS)Release 17TS
When deriving a KAKMA from KAUSF, the following parameters shall be used to form the input S to the KDF:
– FC = 0x80;
– P0 = "AKMA";
– L0 = length of "AKMA"; (i.e. 0x00 0x04)
– P1 = SUPI;
– L1 = length of SUPI.
The input key KEY shall be the KAUSF.
SUPI shall be the same value as parameter P0 in Annex A.7.0 of TS 33.501 [2].