Key processing method in dual connectivity mode and device

1. A key processing method in dual connectivity mode, the method comprising:

receiving, by a second base station, request information sent by a first base station,

wherein the request information is a request that the second base station generate a key used for communication with a mobile terminal, wherein each of the first base station and the second base station has a communication connection to the mobile terminal; and

generating, by the second base station based on a security key currently used by the first base station and carried in the request information, the key used for communication with the mobile terminal;

wherein when the first base station and the second base station generate, based on different security keys, respective keys used for communication with the mobile terminal, the method further comprises:

receiving, by the second base station, first instruction information sent by the first base station after determining that local key refresh needs to be performed,

wherein the first instruction information is used to instruct the second base station to temporarily stop data transmission to the mobile terminal when the local key refresh is being performed;

temporarily stopping, by the second base station, data transmission to the mobile terminal during the local key refresh; and

resuming, by the second base station, data transmission to the mobile terminal after receiving an instruction from the first base station to resume data transmission to the mobile terminal after completion of the local key refresh.

2. A key processing method in dual connectivity mode, the method comprising:

receiving, by a mobile terminal that has a communication connection to a first base station and a communication connection to a second base station, request information sent by the first base station,

wherein the request information is a request that the mobile terminal generates a key used for communication with the second base station;

generating, by the mobile terminal, according to the request information, the key used for communication with the second base station;

receiving, by the mobile terminal, key refresh instruction information sent by the first base station,

wherein the key refresh instruction information is used to instruct the mobile terminal to refresh a key used for communication with the first base station and a key used for communication with the second base station;

generating, by the mobile terminal, a first security key according to information carried in the key refresh instruction information, and

generating, by the mobile terminal, based on the first security key, the key used for communication with the first base station and the key used for communication with the second base station; and

returning, by the mobile terminal, to the first base station, feedback information used to notify that the key refresh has been completed for the first base station and the second base station.

3. The method according to claim 2 , wherein generating the key used for communication with the second base station is according to one of the following:

a security algorithm used by the second base station and the first security key that is generated by the mobile terminal for the first base station; or

a security algorithm used by the second base station and a physical cell identifier (PCI) and frequency information of a cell that are comprised in the request information and that are used to generate a second security key of the second base station; or

a second security key of the second base station generated according to stored security context information.

4. The method according to claim 2 , wherein when the key refresh instruction information further comprises information about a cell that is specified by the first base station or the second base station for random access performed by the mobile terminal, the mobile terminal performs random access in the specified cell.

5. The method according to claim 2 , further comprising:

receiving, by the mobile terminal, key-rekey instruction information sent by the first base station or the second base station, wherein the key-rekey instruction information instructs the mobile terminal to update a key used for communication with the first base station and the key used for communication with the second base station;

generating, by the mobile terminal, a new security key according to stored security context information, and generating, according to the new security key, a key used for communication with the first base station and a key used for communication with the second base station; and

returning, by the mobile terminal to the first base station or the second base station, second reply information used to notify that a key-rekey has been completed.

6. A second base station comprising:

a processor;

a receiver configured to cooperate with the processor to receive request information sent by a first base station, wherein the request information contains a request that the second base station generate a key used for communication with a mobile terminal;

the processor configured to generate, based on a security key currently used by the first base station and carried in the request information, the key used for communication with the mobile terminal, wherein each of the second base station and the first base station has a communication connection to the mobile terminal;

wherein when the first base station and the second base station generate, based on different security keys, respective keys used for communication with the mobile terminal:

the receiver is further configured to receive first instruction information sent by the first base station after determining that local key refresh needs to be performed,

wherein the first instruction information is used to instruct to temporarily stop data transmission related to the mobile terminal when the local key refresh is being performed; and

the processor is further configured to (i) temporarily stop data transmission related to the mobile terminal during the local key refresh and, (ii) after the receiver receives an instruction that is sent by the first base station and that is used to instruct to resume data transmission related to the mobile terminal after completion of the local key refresh, resume data transmission related to the mobile terminal.

7. A mobile terminal with a communication connection to a first base station and a communication connection to a second base station, the mobile terminal comprising:

a processor;

a receiver configured to cooperate with the processor to receive request information sent by the first base station, wherein the request information is a request that the mobile terminal generate a key used for communication with the second base station;

the processor configured to generate, according to the request information, the key used for communication with the second base station;

the receiver is further configured to cooperate with the processor to receive key refresh instruction information sent by the first base station,

wherein the key refresh instruction information is used to instruct the mobile terminal to refresh a key used for communication with the first base station and a key used for communication with the second base station; and

the processor further configured to (i) generate a new security key according to information carried in the key refresh instruction information, (ii) generate, based on the new security key, the key used for communication with the first base station and the key used for communication with the second base station, and (iii) trigger the receiver to return to the first base station, feedback information used to notify that the key refresh has been completed for the first base station and the second base station.

8. The mobile terminal according to claim 7 , wherein the processor is further configured to generate the key used for communication with the second base station according to one of the following:

a security algorithm used by the second base station and a first security key that is generated by the mobile terminal for the first base station; or

a security algorithm used by the second base station and a physical cell identifier (PCI) and frequency information of a cell that are comprised in the request information and that are used to generate a second security key of the second base station; or

a second security key of the second base station generated according to stored security context information.

9. The mobile terminal according to claim 7 , wherein when the key refresh instruction information further comprises information about a cell that is specified by the first base station or the second base station for random access performed by the mobile terminal, the mobile terminal performs random access in the specified cell.

10. The mobile terminal according to claim 7 , wherein:

the receiver is further configured to cooperate with the processor to receive key-rekey instruction information sent by the first base station or the second base station,

wherein the key-rekey instruction information instructs the mobile terminal to update a key used for communication with the first base station and the key used for communication with the second base station; and

the processor is further configured to generate a new security key according to stored security context information, (ii) generate, according to the new security key, a key used for communication with the first base station and a key used for communication with the second base station, and (iii) trigger the receiver to return, to the first base station or the second base station, second reply information to notify that a key-rekey has been completed.