# US 10,320,772 B2 · In-vehicle communication system with verification failure holding circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,772 B2 - Document ID: US10320772B2 - Status: Granted - Kind: B2 - Application number: 15/476,695 - Filed: 2017-03-31 - Published: 2017-07-20 - Granted: 2019-06-11 - Earliest claimed: 2012-10-12 - Assignees: Renesas Electronics Corporation - Applicants: Renesas Electronics Corporation - Inventors: Eriko Ando; Takashi Kawauchi; Toru Owada - Web page: https://patentgrep.com/patent/US10320772B2 ## CPC - H04L 63/0823: {using certificates (cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263)} - H04L 9/30: Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy - H04L 9/3247: {involving digital signatures} - H04L 9/3263: {involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823)} - H04L 2209/84: Vehicles - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract The present invention is directed to solve a problem that time is required for a process related to verification of a public key certificate of a message sender. An in-vehicle device mounted on a vehicle has a memory for holding information of a device which failed in verification of a public key certificate. At the time of performing communication between vehicles or between a vehicle and a roadside device, a check is made to see whether or not information of a device included in a message transmitted matches information of a device which failed and held in the memory. When the information matches, verification of a public key certificate is not performed. ## Claims ### Claim 1 An apparatus comprising: a processing unit configured to receive a message including a public key certificate having device information specifying a sender, a public key, and data to be used when verification of the public key certificate succeeds; and a first holding circuit configured to store device information and a public key of a previously received message whose public key certificate has failed verification by the processing unit, wherein when the message is received, the processing unit checks whether or not the device information included in the message matches the device information stored in the first holding circuit, and wherein when said check indicates a match with stored device information and if the public key and a signature of the public key certificate of the received message are not stored in the first holding circuit, the processing unit is configured to verify a signature of the received message after a verification of the public key certificate of the received message is successful, and wherein when said check indicates a match with stored device information and if the public key and signature of the public key certificate stored in the first holding circuit matches the public key and the signature of the public key certificate of the received message, the processing unit is configured to treat verification of the signature of the received message as a failure. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the processing unit is configured to treat the verification of the received message as a failure when verification of the public key certificate of the received message fails. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the processing unit is configured to verify the public key certificate when a prior verification result for the public key certificate has not been stored. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the apparatus is configured as an in-vehicle communication system. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the message is from another vehicle or a roadside device. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein whether a verification result for the public key certificate of the message is stored is based on at least one of: travel information of a vehicle sending the message; setting information of a roadside device sending the message; travel information of a vehicle receiving the message; information related to expiration date of a public key certificate of another apparatus transmitting the message; and information related to reliability level of the public key certificate. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein a valid time value for device information stored in the first holding circuit is calculated by the processing unit at a time of storage of said device information based on position and/or velocity of the apparatus. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the valid time indicates a limit of time for use of the device information stored in the holding circuit. ### Claim 9 (depends on 1) The apparatus of claim 1, further comprising: a second holding circuit configured to store device information and a public key of a previously received message whose public key certificate has been successfully verified by the processing unit. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein the processing unit is configured to, when a message is received: perform a preliminary check if the device information is stored in the second holding circuit; if the preliminary check indicates that the device information is stored in the second holding circuit, execute a process using the data in the received message without performing a separate verification process on the public key certificate of the received message; and if the preliminary check indicates that the device information is not stored in the second holding circuit, perform said check to determine if the device information is stored in the first holding circuit. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the processing unit is further configured to: store the device information from the received message in the first holding circuit when the separate verification process does not succeed in verification, and store the device information in the second holding circuit when the separate verification process succeeds in verification.