Method and apparatus for identifying security key in next generation mobile communication system
The disclosure relates to a communication scheme and system for converging a 5 th generation (5G) communication system for supporting a data rate higher than that of a 4 th generation (4G) system with an internet of things (IoT) technology. The disclosure is applicable to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, and security and safety-related services) based on the 5G communication technology and the IoT-related technology. The disclosure relates to a method and apparatus for allowing a base station to identify a ciphering key (COUNT value) for security enhancement.
1. A method performed by a terminal in a wireless communication system, the method comprising:
receiving, from a base station, a counter check message for at least one data radio bearer (DRB) including first information, the first information including an identity of a DRB and a first count value associated with the DRB; and
transmitting, to the base station as a response to the counter check message, a counter check response message including second information,
wherein, in case that a most significant bits of a second count value of the terminal associated with the DRB is different from a most significant bits of the first count value associated with the DRB, the second information includes the identity of the DRB and the second count value of the terminal associated with the DRB,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for uplink, the second count value of the terminal associated with the DRB is set to a value of TX_NEXT-1,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for downlink, the second count value of the terminal associated with the DRB is set to a value of RX_NEXT-1, and
wherein the TX_NEXT is a count value of a next packet data convergence protocol (PDCP) service data unit (SDU) to be transmitted and the RX_NEXT is a count value of a next PDCP SDU expected to be received.
2. The method of claim 1 , further comprising:
in case that the DRB is a uni-directional bearer configured for a direction and no count value exists for a given direction which is different from the direction, assuming a count value for the given direction to be 0.
3. The method of claim 1 ,
wherein, in case that an identity of an established DRB is not included in the counter check message, third information is included in the counter check response message, the third information including the identity of the established DRB and a third count value of the terminal associated with the established DRB, and
wherein the third count value of the terminal is set to a value of TX_NEXT-1 in a case of uplink and set to a value of RX_NEXT-1 in a case of downlink.
4. The method of claim 1 ,
wherein, in case that the DRB is not established on the terminal, fifth information is included in the counter check response message, the fifth information including the identity of the DRB, a fifth count value of the terminal associated with the DRB with most significant bits set identical to the most significant bits of the first count value associated with the DRB, and least significant bits set to 0, the fifth count value of the terminal associated with the DRB including an uplink count value and a downlink court value.
5. A method performed by a base station in a wireless communication system, the method comprising:
transmitting, to a terminal, a counter check message for at least one data radio bearer (DRB) including first information, the first information including an identity of a DRB and a first count value associated with the DRB; and
receiving, from the terminal as a response to the counter check message, a counter check response message including second information,
wherein, in case that a most significant bits of a second count value of the terminal associated with the DRB is different from a most significant bits of the first count value associated with the DRB, the second information includes the identity of the DRB and the second count value of the terminal associated with the DRB,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for uplink, the second count value of the terminal associated with the DRB is set to a value of TX_NEXT-1,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for downlink, the second count value of the terminal associated with the DRB is set to a value of RX_NEXT-1, and
wherein the TX_NEXT is a count value of a next packet data convergence protocol (PDCP) service data unit (SDU) to be transmitted and the RX_NEXT is a count value of a next PDCP SDU expected to be received.
6. The method of claim 5 ,
wherein, in case that the DRB is a uni-directional bearer configured for a direction and no count value exists for a given direction which is different from the direction, a count value for the given direction identified to be 0.
7. The method of claim 5 ,
wherein, in case that an identity of an established DRB is not included in the counter check message, third information is included in the counter check response message, the third information including the identity of the established DRB and a third count value of the terminal associated with the established DRB, and
wherein the third count value of the terminal is set to a value of TX_NEXT-1 in a case of uplink and set to a value of RX_NEXT-1 in a case of downlink.
8. The method of claim 5 ,
wherein, in case that the DRB is not established on the terminal, fifth information is included in the counter check response message, the fifth information including the identity of the DRB, a fifth count value of the terminal associated with the DRB with most significant bits set identical to the most significant bits of the first count value associated with the DRB, and least significant bits set to 0, the fifth count value of the terminal associated with the DRB including an uplink count value and a downlink count value.
9. A terminal in a wireless communication system, the terminal comprising:
a transceiver; and
a controller configured to:
receive, via the transceiver from a base station, a counter check message for at least one data radio bearer (DRB) including first information, the first information including an identity of a DRB and a first count value associated with the DRB, and
transmit, via the transceiver to the base station as a response to the counter check message, a counter check response message including second information,
wherein, in case that a most significant bits of a second count value of the terminal associated with the DRB is different from a most significant bits of the first count value associated with the DRB, the second information includes the identity of the DRB and the second count value of the terminal associated with the DRB,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for uplink, the second count value of the terminal associated with the DRB is set to a value of TX_NEXT-1,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for downlink, the second count value of the terminal associated with the DRB is set to a value of RX_NEXT-1, and
wherein the TX_NEXT is a count value of a next packet data convergence protocol (PDCP) service data unit (SDU) to be transmitted and the RX_NEXT is a count value of a next PDCP SDU expected to be received.
10. The terminal of claim 9 ,
wherein in case that the DRB is a uni-directional bearer configured for a direction and no count value exists for a given direction which is different from the direction, the controller is further configured to assume a count value for the given direction to be 0.
11. The terminal of claim 9 ,
wherein, in case that an identity of an established DRB is not included in the counter check message, third information is included in the counter check response message, the third information including the identity of the established DRB and a third count value of the terminal associated with the established DRB, and
wherein the third count value of the terminal is set to a value of TX_NEXT-1 in a case of uplink and set to a value of RX_NEXT-1 in a case of downlink.
12. The terminal of claim 9 ,
wherein, in case that the DRB is not established on the terminal, fifth information is included in the counter check response message, the fifth information including the identity of the DRB, a fifth count value of the terminal associated with the DRB with most significant bits set identical to the most significant bits of the first count value associated with the DRB, and least significant bits set to 0, the fifth count value of the terminal associated with the DRB including an uplink count value and a downlink count value.
13. A base station in a wireless communication system, the base station comprising:
a transceiver; and
a controller configured to:
transmit, via the transceiver to a terminal, a counter check message for at least one data radio bearer (DRB) including first information, the first information including an identity of a DRB and a first count value associated with the DRB; and
receive, via the transceiver from the terminal as a response to the counter check message, a counter check response message including second information,
wherein, in case that a most significant bits of a second count value of the terminal associated with the DRB is different from a most significant bits of the first count value associated with the DRB, the second information includes the identity of the DRB and the second count value of the terminal associated with the DRB,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for uplink, the second count value of the terminal associated with the DRB is set to a value of TX_NEXT-1,
wherein, in case that the first count value associated with the DRB and the second count value of the terminal associated with the DRB are for downlink, the second count value of the terminal associated with the DRB is set to a value of RX_NEXT-1, and
wherein the TX_NEXT is a count value of a next packet data convergence protocol (PDCP) service data unit (SDU) to be transmitted and the RX_NEXT is a count value of a next PDCP SDU expected to be received.
14. The base station of claim 13 ,
wherein, in case that the DRB is a uni-directional bearer configured for a direction and no count value exists for a given direction which is different from the direction, a count value for the given direction identified to be 0.
15. The base station of claim 13 ,
wherein, in case that an identity of an established DRB is not included in the counter check message, third information is included in the counter check response message, the third information including the identity of the established DRB and a third count value of the terminal associated with the established DRB, and
wherein the third count value of the terminal is set to a value of TX_NEXT-1 in a case of uplink and set to a value of RX_NEXT-1 in a case of downlink.
16. The base station of claim 13 ,
wherein, in case that the DRB is not established on the terminal, fifth information is included in the counter check response message, the fifth information including the identity of the DRB, a fifth count value of the terminal associated with the DRB with most significant bits set identical to the most significant bits of the first count value associated with the DRB, and least significant bits set to 0, the fifth count value of the terminal associated with the DRB including an uplink count value and a downlink count value.