Section: B.7 Derivation of Kc' from Kc for UTRAN/GERAN to HSPA SRVCC handover
Content: This input string is used for GSM subscribers when there is a need to derive GPRS Kc' from the 64-bit Kc during mapping the security contexts from UTRAN/GERAN to HSPA. The input parameter Key is the concatenation of Kc || Kc || Kc || Kc || (which are 64 bits each), and the output Kc' is the 64 most significant bits of the KDF output. - FC = 0x34 - P0 = NONCEMSC - L0 = length of NONCEMSC (i.e. 0x00 0x10) CK'PS || IK'PS shall be derived from GPRS Kc' using the key conversion functions c4 and c5 defined in this specification.