Processing Method for Security Algorithm and Terminal

Abstract

Implementations of the present disclosure provide a processing method and apparatus for a security algorithm and a terminal. The method includes the following. A terminal performs cell search and selects a cell supporting a security algorithm as a target cell from found cells, where the security algorithm is used by the terminal before RRC connection re-establishment or RRC connection recovery. The terminal performs an RRC connection re-establishment procedure or an RRC connection recovery procedure between the terminal and the target cell.

What is claimed is: 
     
         1 . A method for processing a security algorithm, comprising:
 performing, by a terminal, cell search, and selecting, by the terminal, a cell supporting a security algorithm as a target cell from found cells, wherein the security algorithm is used by the terminal before radio resource control (RRC) connection re-establishment or RRC connection recovery; and   performing, by the terminal, an RRC connection re-establishment procedure or an RRC connection recovery procedure between the terminal and the target cell.   
     
     
         2 . The method of  claim 1 , further comprising:
 for each of at least one cell, obtaining, by the terminal, a security algorithm list supported by the cell from a system broadcast message of the cell, wherein the security algorithm list contains at least one security algorithm support by the cell.   
     
     
         3 . The method of  claim 1 , wherein performing, by the terminal, the RRC connection re-establishment procedure between the terminal and the target cell comprises:
 transmitting, by the terminal, an RRC connection re-establishment request message to the target cell;   receiving, by the terminal, an RRC connection re-establishment message from the target cell, wherein the RRC connection re-establishment message has been subjected to integrity protection performed with the security algorithm and a secret key updated by the target cell; and   transmitting, by the terminal, an RRC connection re-establishment completion message to the target cell.   
     
     
         4 . The method of  claim 3 , wherein
 the RRC connection re-establishment message carries next hop chaining count (NCC) information, wherein the NCC information is used by the terminal to update a secret key;   the method further comprises:   performing, by the terminal, integrity protection and encryption on the RRC connection re-establishment completion message with the security algorithm and the secret key updated by the terminal.   
     
     
         5 . The method of  claim 1 , wherein performing, by the terminal, the RRC connection recovery procedure between the terminal and the target cell comprises:
 transmitting, by the terminal, an RRC connection recovery request message to the target cell;   receiving, by the terminal, an RRC connection recovery message from the target cell, wherein the RRC connection recovery message has been subjected to integrity protection and encryption performed with the security algorithm and a secret key updated by the target cell; and   transmitting, by the terminal, an RRC connection recovery completion message to the target cell.   
     
     
         6 . The method of  claim 5 , wherein
 the RRC connection recovery message carries NCC information, wherein the NCC information is used by the terminal to update a secret key;   the method further comprises:   performing, by the terminal, integrity protection and encryption on the RRC connection recovery completion message with the security algorithm and the secret key updated by the terminal.   
     
     
         7 . A method for processing a security algorithm, comprising:
 performing, by a terminal, cell search, and selecting, by the terminal, a target cell from found cells;   transmitting, by the terminal, a radio resource control (RRC) connection re-establishment request message to the target cell;   receiving, by the terminal, an RRC connection re-establishment message from the target cell, and determining, by the terminal, whether the RRC connection re-establishment message carries configuration information of a security algorithm supported by the target cell; and   transmitting, by the terminal, an RRC connection re-establishment completion message to the target cell via the security algorithm supported by the target cell, in response to the RRC connection re-establishment message carrying the configuration information of the security algorithm supported by the target cell.   
     
     
         8 . The method of  claim 7 , wherein
 the RRC connection re-establishment message carrying the configuration information of the security algorithm supported by the target cell is indicative of that a security algorithm used by the terminal before RRC connection re-establishment is not supported by the target cell.   
     
     
         9 . The method of  claim 7 , wherein
 the RRC connection re-establishment message not carrying the configuration information of the security algorithm supported by the target cell or carrying the configuration information of the security algorithm supported by the target cell is indicative of that a security algorithm used by the terminal before RRC connection re-establishment is supported by the target cell.   
     
     
         10 . The method of  claim 7 , wherein
 the RRC connection re-establishment message has been subjected to integrity protection performed with the security algorithm supported by the target cell and a secret key updated by the target cell, on condition that the RRC connection re-establishment message carries the configuration information of the security algorithm supported by the target cell.   
     
     
         11 . The method of  claim 7 , wherein
 the RRC connection re-establishment message carries next hop chaining count (NCC) information, wherein the NCC information is used by the terminal to update a secret key;   the method further comprises:   performing, by the terminal, integrity protection and encryption on the RRC connection re-establishment completion message with the security algorithm supported by the target cell and the secret key updated by the terminal, in response to the RRC connection re-establishment message carrying the configuration information of the security algorithm supported by the target cell.   
     
     
         12 . The method of  claim 7 , further comprising:
 transmitting, by the terminal, the RRC connection re-establishment completion message to the target cell via a security algorithm used by the terminal before RRC connection re-establishment, in response to the RRC connection re-establishment message not carrying the configuration information of the security algorithm supported by the target cell.   
     
     
         13 . The method of  claim 12 , wherein
 the RRC connection re-establishment message carries NCC information, wherein the NCC information is used by the terminal to update a secret key; and   the method further comprises:   performing, by the terminal, integrity protection and encryption on the RRC connection re-establishment completion message with the security algorithm used by the terminal before the RRC connection re-establishment and the secret key updated by the terminal, in response to the RRC connection re-establishment message not carrying the configuration information of the security algorithm supported by the target cell.   
     
     
         14 . A terminal comprising:
 at least one processor; and   a memory storing computer programs which, when executed by the at least one processor, cause the at least one processor to:   perform cell search and select a cell supporting a security algorithm as a target cell from found cells, wherein the security algorithm is used by the terminal before radio resource control (RRC) connection re-establishment or RRC connection recovery; and   perform an RRC connection re-establishment procedure or an RRC connection recovery procedure between the terminal and the target cell.   
     
     
         15 . The terminal of  claim 14 , wherein the computer programs further cause the at least one processor to:
 obtain, for each of at least one cell, a security algorithm list supported by the cell from a system broadcast message of the cell, wherein the security algorithm list contains at least one security algorithm support by the cell.   
     
     
         16 . The terminal of  claim 14 , wherein the computer programs causing the at least one processor to perform the RRC connection re-establishment procedure between the terminal and the target cell cause the at least one processor to:
 transmit an RRC connection re-establishment request message to the target cell;   receive an RRC connection re-establishment message from the target cell, wherein the RRC connection re-establishment message has been subjected to integrity protection performed with the security algorithm and a secret key updated by the target cell; and   transmit an RRC connection re-establishment completion message to the target cell.   
     
     
         17 . The terminal of  claim 16 , wherein
 the RRC connection re-establishment message carries next hop chaining count (NCC) information, wherein the NCC information is used by the terminal to update a secret key;   the computer programs further cause the at least one processor to:   perform integrity protection and encryption on the RRC connection re-establishment completion message with the security algorithm and the secret key updated by the terminal.   
     
     
         18 . The terminal of  claim 14 , wherein the computer programs causing the at least one processor to perform the RRC connection recovery procedure between the terminal and the target cell cause the at least one processor to:
 transmit an RRC connection recovery request message to the target cell;   receive an RRC connection recovery message from the target cell, wherein the RRC connection recovery message has been subjected to integrity protection and encryption performed with the security algorithm and a secret key updated by the target cell; and   transmit an RRC connection recovery completion message to the target cell.   
     
     
         19 . The terminal of  claim 18 , wherein
 the RRC connection recovery message carries NCC information, wherein the NCC information is used by the terminal to update a secret key;   the computer programs further cause the at least one processor to:   perform integrity protection and encryption on the RRC connection recovery completion message with the security algorithm and the secret key updated by the terminal.   
     
     
         20 . The terminal of  claim 14 , wherein the target cell has the highest signal quality among the found cells.