Abstract: A transmission device transmits multiplexed signals obtained by multiplexing signals of N systems corresponding to N Orbital Angular Momentum (OAM) propagation modes. The transmission device includes: an array antenna that includes M antenna elements disposed in a lattice on a plane when viewed from the plane; and a transmitter that multiplies signals obtained by branching each of the signals of N systems into M signals by weighting coefficients of phase shift angles based on angles of the respective M antenna elements with respect to a reference axis passing through a reference point viewed from the reference point on the plane according to the OAM propagation modes, multiplexes the signals of N systems multiplied by the weighting coefficients of the phase shift angles, and transmits signals obtained by the multiplexing from the M antenna elements. M and N are integers equal to or larger than 2.

Abstract: A transmission device transmits multiplexed signals obtained by multiplexing signals of N systems corresponding to N Orbital Angular Momentum (OAM) propagation modes. The transmission device includes: an array antenna that includes M antenna elements disposed in a lattice on a plane when viewed from the plane; and a transmitter that multiplies signals obtained by branching each of the signals of N systems into M signals by weighting coefficients of phase shift angles based on angles of the respective M antenna elements with respect to a reference axis passing through a reference point viewed from the reference point on the plane according to the OAM propagation modes, multiplexes the signals of N systems multiplied by the weighting coefficients of the phase shift angles, and transmits signals obtained by the multiplexing from the M antenna elements. M and N are integers equal to or larger than 2.

Abstract: A transmission device includes: a modulator that selects an Orbital Angular Momentum (OAM) propagation mode among N (N is an integer equal to or greater than 2) OAM propagation modes in accordance with a value of bit data to be transmitted; and a transmitter that transmits a signal of the OAM propagation mode selected by the modulator.

Abstract: 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.

Abstract: A rewrite detection system, a rewrite detection device and an information processing device can detect unauthorized rewrite to a program or data stored in a storage unit of the information processing device. A rewrite detection device generates a random seed and transmits it to an ECU and a server device. The ECU calculates a hash value using a predetermined hash function on the basis of the received random seed and the storage content of the storage unit, and transmits the hash value to the rewrite detection device. The server device transmits an expectation in response to an inquiry from the rewrite detection device. The rewrite detection device determines whether unauthorized rewrite to a program or data in the ECU has been performed or not in accordance with whether the expectation received from the server device and the hash value received from the ECU coincide with each other or not.

Abstract: An access restriction device as well as an on-board communication system and a method for communication restriction, which prevent outside leakage of information caused by unauthorized access of malicious programs to an in-car network. The communication between the in-car network of the vehicle and an external device is performed by a security controller. The security controller can perform addition or update of a program involving processing for transmission and reception of the information. The security controller performs processing for restricting access to information of the in-car network performed by program execution according to an access authorization level of each program and an access permission level of each type of information. The security controller restricts the transmission depending on the access authorization level of each program and the access permission level of each type of information in case of transmitting the information to the in-car network by the program execution.

Abstract: A communication system and a comparison method for securing a communication path for a legitimate user via a terminal apparatus (“TA”). A vehicle-mounted communication device (“VMCD”) transmits a device ID identifying the VMCD to a TA, acquires a terminal ID from the TA, and transmits the device ID and the terminal ID acquired from the TA to a central apparatus. The TA transmits a terminal ID identifying the TA to the VMCD, acquires a device ID from the VMCD, and transmits the terminal ID and the device ID acquired from the VMCD to the central apparatus. The central apparatus receives a device ID and a terminal ID transmitted from the VMCD and a device ID and a terminal ID transmitted from the TA, and compares the device ID and the terminal ID received from the VMCD with the device ID and the terminal ID received from the TA.

Abstract: 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.

Abstract: 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.

Abstract: 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 t0 for periodical message transmission by an ECU, decides multiple scheduled transmission time points t1, t2, . . . obtained by adding a period corresponding to an integer multiple of a transmission cycle T of a message to the reference time point t0, 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.

Abstract: Provided are a rewrite detection system and an information processing device capable of reducing communication traffic between devices and processing time in each device. A rewrite detecting device generates a random seed and transmits the random seed to an ECU, the ECU calculates a hash value using a predetermined hash function, and transmits the hash value to a rewrite detecting device. The ECU decides a storage region serving among storage regions of the storage unit, and calculates the hash value. The rewrite detecting device determines whether the hash value received from the ECU is right or wrong, and determines whether or not fraudulent rewrite has been performed. The ECU designates a storage region which is apart from a storage region used as a previous hash value calculation target by a predetermined address as a storage region of a current processing target.

Abstract: 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.

Abstract: A plurality of ECUs and a monitoring device are connected to a common CAN bus. Each ECU outputs to the CAN bus a transmission frame where authentication information is added to data to be transmitted to the other ECUs. The monitoring device monitors transmission of a frame to the CAN bus, obtains a frame when the frame is transmitted, and determines right or wrong of authentication information contained in the obtained frame. When the authentication information is not right, there is a possibility that the transmission frame is a fraudulent frame transmitted by malicious equipment, therefore, the monitoring device outputs an error frame to the CAN bus before a final bit of an EOF of the transmission frame is outputted to the CAN bus, and causes the EUCs to discard this transmission frame.

Abstract: A program update system and method that are able to verify the legitimacy of an update of a program executed on a vehicle side. An exterior device stores update data including an update control program for a control device targeted for updating and a computer program that implements means for calculating a digest value relating to the update control program, means for determining whether operation of the control device after the update is normal, and means for transmitting a result of the determination as a response. The control device to receives the update data that is transmitted from the exterior device via a relay device and updates the control program using the update control program included in the update data, and determines whether operation after the update is normal and transmits a result of the determination to the relay device by executing the computer program.

Abstract: A connection detection apparatus in includes a gateway to which communication lines are connected, and which detects whether an unauthorized communication device has been connected to the communication lines. The gateway samples a signal several times from each of the communication lines, and generates waveform information, such as an eye pattern in which the waveforms are superimposed on one another. Furthermore, the gateway has stored therein normal waveform information, such as a mask generated based on the eye pattern at normal times. The gateway compares the generated waveform information with the stored waveform information, and recognizes that the waveform information is abnormal if it does not sufficiently match the normal waveform information. If the waveform information is abnormal, it is determined that an unauthorized communication device has been connected to one or more of the communication lines.

Abstract: A rewrite detection system, a rewrite detection device and an information processing device can detect unauthorized rewrite to a program or data stored in a storage unit of the information processing device. A rewrite detection device generates a random seed and transmits it to an ECU and a server device. The ECU calculates a hash value using a predetermined hash function on the basis of the received random seed and the storage content of the storage unit, and transmits the hash value to the rewrite detection device. The server device transmits an expectation in response to an inquiry from the rewrite detection device. The rewrite detection device determines whether unauthorized rewrite to a program or data in the ECU has been performed or not in accordance with whether the expectation received from the server device and the hash value received from the ECU coincide with each other or not.

Abstract: An access restriction device as well as an on-board communication system and a method for communication restriction, which prevent outside leakage of information caused by unauthorized access of malicious programs to an in-car network. The communication between the in-car network of the vehicle and an external device is performed by a security controller. The security controller can perform addition or update of a program involving processing for transmission and reception of the information. The security controller performs processing for restricting access to information of the in-car network performed by program execution according to an access authorization level of each program and an access permission level of each type of information. The security controller restricts the transmission depending on the access authorization level of each program and the access permission level of each type of information in case of transmitting the information to the in-car network by the program execution.

Abstract: A connection detection apparatus in includes a gateway to which communication lines are connected, and which detects whether an unauthorized communication device has been connected to the communication lines. The gateway samples a signal several times from each of the communication lines, and generates waveform information, such as an eye pattern in which the waveforms are superimposed on one another. Furthermore, the gateway has stored therein normal waveform information, such as a mask generated based on the eye pattern at normal times. The gateway compares the generated waveform information with the stored waveform information, and recognizes that the waveform information is abnormal if it does not sufficiently match the normal waveform information. If the waveform information is abnormal, it is determined that an unauthorized communication device has been connected to one or more of the communication lines.

Abstract: A wireless network system including a first terminal for sending a request-to-send signal including information on a medium use period to a second terminal before sending data, receiving a clear-to-send signal from the second terminal, and sending data to the second terminal during the medium use period; the second terminal for receiving the request-to-send signal and sending the clear-to-send signal; a third terminal for receiving the request-to-send signal and transmitting data to a fourth terminal during the medium use period; and the fourth terminal. Thus, it is possible to prevent occurrence of a problem that when it is judged that the wireless channel is being used, transmission of the station is suppressed.

Abstract: In a communication system that performs recharging operation and short-range data communication between a portable terminal and a cradle, when a communication unit of the cradle is halted for power saving purpose, there is no unit available to activate the communication unit of the cradle through operation of the portable terminal when data communication is commenced while the portable terminal remains placed in the cradle. A first control unit 22 activates a first communication unit 24 according to an output of an open state detection unit 23 that detects an open state of a portable terminal 20. A second control unit 27 activates a second communication unit 26 of the cradle according to an output of an opened terminal detection unit 25 that detects placement of the opened portable terminal 20. As a result, the first communication unit 24 and the second communication unit 26 are activated by opening the portable terminal 20, whereby bidirectional communication can be established therebetween.