Patent ID: 8452007

Claim:
A security key generating method, for generating a security key in the course of the user equipment handover from other network to the Evolved UMTS Terrestrial Radio Access Network (EUTRAN), comprising: generating, by a mobility management entity, a security key based on a root key K ASME of the EUTRAN network, and a specific value and/or other parameters, wherein the mobility management entity generates the root security K ASME of the EUTRAN network based on a received forward relocation request message; transmitting to a target evolved Node-B (eNB) a handover request message carrying the security key; generating, by the user equipment, the security key used by the target eNB based on the root key K ASME of the EUTRAN network, and a specific value and/or other parameters; after the target eNB receives the security key, receiving, by the mobility management entity, a handover request acknowledge message corresponding to the handover request message, and sending a forward relocation response message corresponding to the forward relocation request message to a Serving General Packet Radio Service Support Node (SGSN) of the current network; receiving, by the SGSN of the current network, the forward relocation response message, and transmitting a relocation command message; transmitting, by a Radio Network Controller (RNC) of the current network, a handover command message to the user equipment; and generating, by the user equipment, a root key K ASME of the EUTRAN network based on the received handover command message.