Patent ID: 11877150
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 13:
14. A communication apparatus, comprising:
at least one processor coupled to at least one memory storing program instructions and configured to execute the program instructions to cause the communication apparatus to:
send, to a source mobility management network element, a first initial non-access stratum (NAS) message from a terminal, wherein the first initial NAS message comprises a first non-cleartext information element that is security protected by using a first root key;
receive a second root key and first indication information from the source mobility management network element, wherein the first indication information indicates that the second root key is a root key obtained by updating the first root key; and
send second indication information and third indication information to the terminal based on the first indication information, wherein the second indication information indicates the terminal to update the first root key stored by the terminal to obtain the second root key, the third indication information indicates the terminal to send a second initial NAS message the second initial MAS message comprises a second non-cleartext information element that is security protected by using the second root key, and content of the second non-cleartext information element is the same as that of the first non-cleartext information element.