In 3G-UMTS, CK/IK are directly used by RNCand UE to encrypt data/signaling;
In 4G-LTE, CK/IK are used to derive out theKasme by HSS/USIM, then Kasme is used to derive out Knasenc/Knasint/KeNB by MMEand UE for encrypting NAS signlaing, KeNB is sent to eNB, then it is used byeNB and UE to derive out Krrcenc/Krrcint/Kupenc for encrypting encrypting RRCsignling and user data.
Here NH=nextHopChainingCount is provided byeNB during HO.