Method and device for verifying key requester

A device for verifying a key requester, comprising:

• a transceiver, configured to receive a request message sent by a first core-network network element, wherein the request message carries an identifier of the first core-network network element, identity information of a user equipment (UE), and a first token;
• and
• at least one processor in communication with a memory storing one or more instructions, wherein the processor executes the instructions to:
• determine to provide a key for the first core-network network element when determining, based on the identifier of the first core-network network element and the identity information of the UE, that the first token is valid
• wherein the device further comprises:
• the at least one processor configured to:
• generate a first fresh parameter before receiving the request message sent by the first core-network network element;
• and
• the transceiver configured to:
• send the first fresh parameter to a second core-network network element, wherein the second core-network network element generates the first token based on the identifier of the first core-network network element to which the UE attaches, the identity information of the UE, the first fresh parameter, and a shared key.