Counter check and reconfiguration method, apparatus, and system

A terminal, comprising:

• a receiver, configured to receive reconfiguration information that is sent by a primary base station and carries an encryption algorithm of a secondary base station, and transmit the reconfiguration information carrying the encryption algorithm to a processor;
• wherein the processor is configured to receive the reconfiguration information carrying the encryption algorithm from the receiver, update a local key according to the encryption algorithm in the reconfiguration information and use the encryption algorithm and the updated key to communicate with the secondary base station, and transmit the updated key information to a transmitter;
• and
• wherein the transmitter is configured to receive the updated key information from the processor, and send reconfiguration complete information to the primary base station, so that the primary base station knows, according to the reconfiguration complete information, information that the primary base station completes a reconfiguration.

A system comprising:

• a primary base station configured to:
• receive security parameter update request information that is sent by a secondary base station, wherein the security parameter update request information comprises a encryption algorithm,
• add the encryption algorithm in the received security parameter update request information to reconfiguration information, and
• send the reconfiguration information carrying the encryption algorithm to a terminal, and receive reconfiguration complete information sent by the terminal;
• and
• wherein the secondary base station is configured to:
• determine an encryption algorithm used by the secondary base station and the terminal,
• send security parameter update request information to the primary base station, wherein the security parameter update request information comprises the encryption algorithm, and
• communicate with the terminal by using a updated key, the updated key is updated based on the encryption algorithm.