# US 12,015,915 B2 · Communication method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,015,915 B2 - Document ID: US12015915B2 - Status: Granted - Kind: B2 - Application number: 17/513,405 - Filed: 2021-10-28 - Published: 2022-02-17 - Granted: 2024-06-18 - Earliest claimed: 2019-04-29 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Tingting Geng; Haiyan Luo; Le Yan; Qinghai Zeng - Web page: https://patentgrep.com/patent/US12015915B2 ## CPC - H04W 12/0431: Key distribution or pre-distribution; Key agreement - H04W 12/108: Source integrity - H04W 12/106: Packet or message integrity - H04W 12/122: Counter-measures against attacks; Protection against rogue devices - H04W 36/08: Reselecting an access point - H04W 48/12: using downlink control channel - H04W 84/042: {Public Land Mobile systems, e.g. cellular systems} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract This application provides a communication method and apparatus, and relates to the field of communication technologies. The method may include: A network device performs integrity protection on system information by using a first private key, and sends the system information, where the system information includes a first public key corresponding to the first private key and/or an index of the first public key. Correspondingly, a terminal device receives the system information from the network device, and if determining that the first public key is valid, the terminal device verifies integrity of the system information by using the first public key. According to this method, on one hand, the terminal device can effectively identify validity of the system information. On the other hand, because the system information includes the first public key and/or the index of the first public key, flexible update of an asymmetric key can be implemented. ## Claims ### Claim 1 A communication apparatus, wherein the communication apparatus comprises: a processor, the processor is coupled to a memory, and the memory is configured to store instructions, and when the instructions are run by the processor, the communication apparatus is enabled to perform: receiving first system information from a first network device, wherein the first system information comprises at least one of: a first public key; and an index of the first public key; responsive to determining that the first public key is valid, verifying integrity of the first system information by using the first public key, and responsive to the integrity verification on the first system information fails, recording a failure report, wherein the failure report comprises information about (1) a first cell, (2) location information, and (3) an exception cause. ### Claim 2 (depends on 1) The communication apparatus according to claim 1, wherein integrity protection is performed on the first system information based on a first private key corresponding to the first public key. ### Claim 3 (depends on 1) The communication apparatus according to claim 1, wherein the determining that the first public key is valid comprises: receiving public key information, wherein the public key information comprises at least one public key; and responsive to the at least one public key comprising the first public key, determining that the first public key is valid. ### Claim 4 (depends on 3) The communication apparatus according to claim 3, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: receiving indication information, wherein the indication information is used to indicate a valid area to which the public key information is applicable. ### Claim 5 (depends on 4) The communication apparatus according to claim 4, wherein the indication information comprises an identifier of the valid area to which the public key information is applicable; and the identifier of the valid area comprises at least one of the following: a public land mobile network identifier; a radio access network notification area identifier; a tracking area identity; a cell identifier; and a private network identifier. ### Claim 6 (depends on 4) The communication apparatus according to claim 4, wherein the indication information is used to indicate that the valid area to which the public key information is applicable is a tracking area list of a terminal device; or the indication information is used to indicate that the valid area to which the public key information is applicable is a radio access network notification area of the terminal device. ### Claim 7 (depends on 1) The communication apparatus according to claim 1, wherein the determining that the first public key is valid comprises: receiving public key information, wherein the public key information comprises at least one public key and an index of the at least one public key; and responsive to the at least one public key comprising the first public key, and the index of the at least one public key comprising the index of the first public key, determining that the first public key is valid. ### Claim 8 (depends on 1) The communication apparatus according to claim 1, wherein the exception cause comprises at least one of the following: integrity verification on the first system information fails, the first cell is a fake cell, and the first network device is a fake network device. ### Claim 9 (depends on 8) The communication apparatus according to claim 8, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: performing reselection from the first cell to a second cell; and sending the failure report to a second network device to which the second cell belongs. ### Claim 10 (depends on 9) The communication apparatus according to claim 9, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: before the sending the failure report to the second network device, determining that verification on second system information sent by the second network device succeeds. ### Claim 11 A communication apparatus, wherein the communication apparatus comprises: a processor, the processor is coupled to a memory, and the memory is configured to store instructions, and when the instructions are run by the processor, the communication apparatus is enabled to perform: performing integrity protection on first system information by using a first private key; sending the first system information, wherein the first system information comprises a first public key corresponding to at least one of: the first private key and an index of the first public key; and receiving a failure report sent by the terminal device, wherein the failure report comprises (1) information about a third cell, (2) location information of the terminal device, and (3) an exception cause. ### Claim 12 (depends on 11) The communication apparatus according to claim 11, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: receiving private key information from a core network device, wherein the private key information comprises at least one private key and at least one public key corresponding to the at least one private key, and the first private key is one of the at least one private key. ### Claim 13 (depends on 12) The communication apparatus according to claim 12, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: sending public key information to a terminal device, wherein the public key information comprises the at least one public key. ### Claim 14 (depends on 13) The communication apparatus according to claim 13, wherein the exception cause comprises at least one of the following: integrity verification on the first system information fails, the third cell is a fake cell, and a third network device to which the third cell belongs is a fake network device. ### Claim 15 (depends on 11) The communication apparatus according to claim 11, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: receiving private key information from a core network device, wherein the private key information comprises at least one private key and an index of the at least one private key, the first private key is one of the at least one private key, and an index of the first private key is the same as the index of the first public key. ### Claim 16 (depends on 15) The communication apparatus according to claim 15, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: receiving at least one public key from the core network device, wherein the at least one public key is in a one-to-one correspondence with the at least one private key; and sending public key information to a terminal device, wherein the public key information comprises the at least one public key and an index of the at least one public key. ### Claim 17 (depends on 16) The communication apparatus according to claim 16, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: receiving indication information from the core network device, wherein the indication information is used to indicate a valid area to which the public key information is applicable. ### Claim 18 (depends on 17) The communication apparatus according to claim 17, wherein when the instructions are run by the processor, the communication apparatus is further enabled to perform: sending the indication information to the terminal device, wherein the indication information is used to indicate the valid area to which the public key information is applicable. ### Claim 19 (depends on 17) The communication apparatus according to claim 17, wherein the indication information comprises an identifier of the valid area to which the public key information is applicable; and the identifier of the valid area comprises at least one of the following: a public land mobile network identifier; a radio access network notification area identifier; a tracking area identity; a cell identifier; and a private network identifier. ### Claim 20 (depends on 17) The communication apparatus according to claim 17, wherein the indication information is used to indicate that the valid area to which the public key information is applicable is a tracking area list of the terminal device; or the indication information is used to indicate that the valid area to which the public key information is applicable is a radio access network notification area of the terminal device.