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TechSpec
  • Foreword
  • 1 Scope
  • 2 References
  • 3 Definitions of terms, symbols and abbreviations
  • 4 Overview
  • 5 Common security procedures
  • 6 Security for 5G ProSe features
  • 7 5G ProSe services
  • A.1 KDF interface and input parameter construction
  • A.2 CP-PRUK derivation function
  • A.3 Derivation of CP-PRUK ID*
  • A.4 KNR_ProSe derivation function
  • A.5 Calculation of DCR confidentiality keystream
  • A.6 Calculation of MIC value for discovery message
  • A.7 Message-specific confidentiality mechanisms for discovery
  • A.8 Calculation of KNRP for UE-to-Network relays
  • A.9 Calculation of MIC value for Direct Communication Request

A.4 KNR_ProSe derivation function

33.5033GPPRelease 17Security Aspects of Proximity based Services (ProSe) in the 5G System (5GS)TS

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

When deriving the KNR_ProSe from CP-PRUK key, the following parameters shall be used to form the input S to the KDF:

– FC = 0x87;

– P0 = Nonce_2;

– L0 = length of Nonce_2;

– P1 = Nonce_1;

– L1 = length of Nonce_1.

The input key KEY shall be CP-PRUK key.