 for the protection of NAS traffic with a particular integrity algorithm. This key is derived by the UE and MME from KASME as well as an identifier for the integrity algorithm. USIM AuC CK, IK UE HSS KASME UE/MME Knas enc KNAS int UE / eNB KUP enc KRRC enc KRRC int FIGURE 8-7 Key derivation procedure in 3GPP LTE [7] 8.8 3GPP LTE security aspects KNASenc is a key which is only used for the protection of NAS traffic with a particular encryption algorithm. This key is derived by the UE and MME from KASME, as well as an identifier for the encryption algorithm. KeNB is a key derived by the UE and MME from KASME. KeNB may also be derived by the target eNB from the Next Hop (NH) during handover. KeNB is used for the derivation of KRRCint, KRRCenc, and KUPenc, for the derivation of KeNB* on handover. KeNB* is a key derived by the UE and source eNB from either KeNB or from a fresh NH. KeNB* is used by the UE and target eNB as a new KeNB for RRC and user-plane traffic. KUPenc is a key which is only used for the protection of user-plane traffic with a particular encryption algorithm. This key is derived by the UE and eNB from KeNB, as well as an identifier for the encryption algorithm. KRRCint is a key which is only used for the protection of RRC traffic with a particular integrity algorithm. KRRCint is derived by the UE and eNB from KeNB, as well as an identifier for the integrity algorithm. KRRCenc is a key which is only used for the protection of RRC traffic with a particular encryption algorithm. KRRCenc is derived by the UE and eNB from KeNB, as well as an identifier for the encryption algorithm. The Next Hop is used by the UE and eNB in the derivation of KeNB* for the provision of Forward Security. The NH is derived by the UE and MME from KASME and KeNB when the security context is established or from KASME and the previous NH. Next Hop Chaining Count (NCC) is a counter related to NH, i.e., the amount of key chaining that has been performed, which allows the UE to be synchronized with the eNB and to determine whether 