Sumitomo Electric Industries, Limited

Sumitomo Wiring Systems, Limited

Autonetworks Technologies, Limited

Nagoya University

Tokai National Higher Education and Research System

Ryo Kurachi

Hiroaki Takada

Hiroshi Ueda

Yukihiro Miyashita

Naoki Adachi

Satoshi Horihata

Shinya Honda

Masanobu Nishimura

Hideki Yamamoto

Gang Zeng

An in-vehicle communication device on a transmitting side of a message includes: a delay time measuring unit measuring a delay time from when transmission of a message is first attempted to when the transmission of the message is started; and an assigning unit assigning the delay time measured by the delay time measuring unit to the message. An in-vehicle communication device on a receiving side of a message includes: a reception point acquisition unit acquiring a point in time when a message from the in-vehicle communication device on the transmitting side is received; a delay time acquisition unit acquiring a delay time assigned to the received message; and a calculation unit calculating a transmission cycle of each message based on a point in time acquired by the reception point acquisition unit and a delay time acquired by the delay time acquisition unit for each of two received messages.

In-vehicle communication system, in-vehicle communication device, and transmission cycle calculation method

A communication device that can prevent the transmission of a message from being continuously hindered over a long period of time, a communication system and a message arbitration method are provided. The communication device transmits and receives a message to and from another device connected to a common communication line which comprises a calculation unit that calculates as to a message to be transmitted a margin time before a time when a transmission of the message is completed; a transmission unit that transmits the message to which information related to the margin time calculated by the calculation unit is attached; and an arbitration unit that performs arbitration based on the information attached to the message when simultaneous message transmissions to the communication line occur, and as to multiple of messages simultaneously transmitted to the communication line, the arbitration unit performs arbitration in such a manner as to prioritize a message with a shorter margin time.

Communication device, communication system and message arbitration method

A communication device stores a first secret key and a first public key, and the on-vehicle authentication device stores a second secret key, a second public key and a signature verification key. The on-vehicle authentication device acquires the first public key, verifies the authenticity of the electronic signature using a signature verification key, encrypts the second public key using the authentic first public key and transmits the encrypted second public key. The communication device receives the encrypted second public key, decrypts the encrypted second public key using the first secret key, encrypts the first public key using the decrypted second public key. The on-vehicle authentication device receives the encrypted first public key, decrypts the encrypted first public key using the second secret key, and authenticates that the communication device is an authentic device when the decrypted first public key has been determined to be authentic.

On-vehicle authentication system, communication device, on-vehicle authentication device, communication device authentication method and communication device manufacturing method

Provided are a communication system and a communication device that allow a reception node to estimate delay time, a generation time point or the like of a message. A delay time estimation part in an ECU determines whether a message received by itself is transmitted in sequence with another message without being provided with time information by a transmission node. If the received message is transmitted in sequence with another message, the received message may be delayed due to arbitrary processing. Thus, the delay time estimation part checks the priority of one or more sequential messages preceding the received message, and estimates delay time of the received message occurring due to the arbitrary processing in accordance with the priority of each message. A generation time point estimation part estimates the time point when the received message is generated by an ECU, based on the delay time estimated.

Communication system and communication device

Provided are a CAN communication system and an error information recording device that may be expected to facilitate identification of the cause of any error occurring in communication. The monitoring device is connected to a CAN bus and determines whether or not an error is included in a message transmitted by an ECU. In the case where an error is included in the transmitted message, the monitoring device records, in the recording unit, information concerning the error in the message as error information. Furthermore, the monitoring device comprises the CAN controller performing communication in accordance with the CAN protocol and the processor performing various types of information processing. The CAN controller may determine whether or not an error is included in message transmission, and if determined that an error is included, may notify the processor of the CAN-ID attached to the message by an interrupt.

Controller area network (CAN) communication system and error information recording device

A relay device capable of preventing transmission of an improper message to one or more networks even if improper falsification is made to a program for executing relay processing. If one CAN controller receives a message, a gateway stores the received message in the message storage unit and also sends the message to the processing unit. The processing unit that received the message performs processing necessary for relay of the message by executing a relay program, and sends the message to be relayed to the CAN controller. The gateway compares the message before being sent from the CAN controller to the processing unit with the message sent from the processing unit to the CAN controller, to determine the properness of the message.

Relay device

Provided are a communication control device and a communication system capable of detecting message transmission in the case where an invalid device transmits a message to a common communication line. A monitoring device decides a reference time point tfor periodical message transmission by an ECU, decides multiple scheduled transmission time points t, t, . . . obtained by adding a period corresponding to an integer multiple of a transmission cycle T of a message to the reference time point t, and decides that a predetermined period including each of the scheduled transmission time points is a permission period for message transmission. The monitoring device determines whether or not a detected message on a CAN bus has been transmitted during the permission period. If determined that transmission of an invalid message is not permitted, the monitoring device performs processing of causing the ECU which receives the message to discard the message.

Communication control device and communication system

A communication device capable of detecting transmission of an improper message to a network. A CAN controller in the gateway transmits and receives a message attached with a priority level (ID) to/from an ECU through a communication line, and counts, by the consecutive block number counter, the number of transmitted messages that are consecutively blocked as a result of arbitration processing as the number of consecutive blocks and stores the number as the number of allowed blocks into an allowed block number table in the storage unit in association with a priority level attached to the message received at the communication line. Every time a message is received, the controller compares the number of consecutive blocks with the number of allowed blocks for this message, and detects abnormality if the number of consecutive blocks is larger than the number of allowed blocks.

Communication device for detecting transmission of an improper message to a network

Provided are a communication device and a communication restriction program capable of suppressing invalid message transmission to a network by injecting an invalid program. The ECU includes a CAN controller having a register group storing a value concerning communication with a different ECU and a processing unit processing a value for the register group. The ECU switches the mode between the full control mode in which writing and reading are allowed for the register group in the CAN controller and the restriction mode wherein writing and reading are restricted for a part of the registers in the register group. The ECU sets a predetermined period from activation corresponding to the full control mode, and switches the full control mode to the restriction mode after the predetermined period elapses. After switching to the restriction mode, the ECU will not switch the mode to the full control mode.

Communication device and non-transitory recording medium

Provided are a communication system, an abnormality detection device and an abnormality detection method that detects abnormality concerning communication such as information forged by utilizing a difference in timings of sampling between multiple communication devices. For the system configuration where ECUs transmit and receive information through a common communication line, abnormality detection related to communication is performed by a monitoring device connected to the communication line. Each ECU receives information by sampling once at a predetermined timing during a transmission period of one-bit information. The ECUs may also be allowed to perform sampling at different timings. The monitoring device samples the voltage of the communication line multiple times over a predetermined monitoring period including a timing of the earliest sampling and a timing of the latest timing performed by the ECUs during the transmission period of one-bit information, and detects abnormality based on the results of multiple times of sampling.

Communication system, abnormality detection device and abnormality detection method

A communication system and key information sharing method which allows first and second communication devices to share key information and perform cryptograph processing. The monitoring device calculates hash value based on copy data of storage content of an ECU, and transmits a part to the ECU as confirmation information. The ECU further extracts a part from a value, obtained by removing confirmation information from hash value calculated by the ECU, and transmits part to the monitoring device as response information when the received confirmation information is included in the hash value calculated by the ECU. The monitoring device determines whether the received response information is included in hash value of the monitoring device or not. The ECU and monitoring device each use residual value, obtained by removing confirmation information and response information from hash value calculated by the ECU or monitoring device, for following cryptograph processing as a shared key.

Communication system and key information sharing method

In a network in which a plurality of ECUs are connected to one another with a common bus, one or more slots are allocated to each ECU in advance, and the plurality of ECUs cyclically transmit messages in an order prescribed in relation to the slots. When each ECU transmits the message related to one slot, each ECU creates and transmits a message including data to be transmitted to other ECUs, and information representing respectively a success/failure of the message reception related to other slots. Each ECU checks information of ACK field included in a message received during one cycle from message transmission related to one slot to a next message transmission related to said one slot. When the message related to one slot is not accurately received by the other ECUs, retransmits the message in the next transmission related to said one slot.

Communication system and communication apparatus

Distribution apparatuses include databases for storing data received from ECUs, and further include receiving buffers and sending buffers. The distribution apparatus continuously performs, in parallel, an operation for storing received data on the receiving buffer, operation for synchronizing contents of the database with the databases, and an operation for sending data from the sending buffer. Further, the distribution apparatus periodically copies data of the receiving buffer onto the database and data of the database onto the sending buffer.

Distribution apparatus, communication system and communication method

Relay apparatuses read the attribute values of data, i.e., numerical information representing measurement values, calculation values, control values, etc., from receive buffers in which data received from ECUs connected thereto is stored, and create trunk frames containing the numerical information and transmit and receive trunk frames via trunk lines. The relay apparatuses derive numerical information from trunk frames received from the other relay apparatuses and renew the numerical information on the data stored in their respective databases using the derived numerical information.

Relay apparatus, communication system and communication method

When communication is performed with the upstream and downstream sides being defined in the order of relay apparatuses, the relay apparatuses each transmit a keepalive message representing that they are effectively performing communication. When no keepalive message can be received from the relay apparatus and an abnormality is detected thereby, the relay apparatus transmits a keepalive message including abnormality information representing that the abnormality is detected. By receiving the keepalive message including the abnormality information, the relay apparatus detects the abnormality on the upstream side, changes a communication path, and transmits a master candidate notification to the relay apparatus on the downstream side in order that the relay apparatus itself becomes a master.

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Nagoya, Japan

Ryo Kurachi