A.10 NH derivation function

33.5013GPPRelease 18Security architecture and procedures for 5G SystemTS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

When deriving a NH from K_AMF the following parameters shall be used to form the input S to the KDF.

– FC = 0x6F

– P0 = SYNC-input

– L0 = length of SYNC-input (i.e. 0x00 0x20)

The SYNC-input parameter shall be the newly derived K_gNB for the initial NH derivation, and the previous NH for all subsequent derivations. This results in a NH chain, where the next NH is always fresh and derived from the previous NH.

The input key KEY shall be the 256-bit K_AMF.