Abstract: A log determination device is configured to acquire a plurality of security logs each including an abnormality information and a position information, store an occurrence pattern of a security log which is predicted to occur due to a maintenance, and compare the plurality of security logs with the occurrence pattern to determine whether or not the plurality of security logs is a false positive log.

Abstract: A log determination device comprises a log acquisition unit that is configured to acquire a security log generated upon detecting an abnormality in an electronic control system, and a false positive log determination unit that is configured to determine, based on a frequency of generation of the security log, whether or not the detected security log is a false positive log, and to output a determination result, wherein the false positive log is the security log generated by detecting the abnormality caused not by the electronic control system being attacked.

Abstract: A message monitoring system includes a first electronic control unit and a second electronic control unit connected to the first electronic control unit via a communication network. In the first electronic control unit, a first message is generated; a first feature value representing a feature of the first message is calculated; a second message storing the first feature value is generated; and the first message is transmitted whereas the second message is transmitted periodically. In the second electronic control unit, the first message and the second message are received from the first electronic control unit; a second feature value representing a feature of the received first message is calculated; and a comparison is performed between (i) the first feature value stored in the received second message and (ii) the calculated second feature value; and whether the first message is normal is determined based on a result of the comparison.

Abstract: A message monitoring system includes a first electronic control unit and a second electronic control unit connected to the first electronic control unit via a communication network. In the first electronic control unit, a first message is generated; a first feature value representing a feature of the first message is calculated; a second message storing the first feature value is generated; and the first message is transmitted whereas the second message is transmitted periodically. In the second electronic control unit, the first message and the second message are received from the first electronic control unit; a second feature value representing a feature of the received first message is calculated; and a comparison is performed between (i) the first feature value stored in the received second message and (ii) the calculated second feature value; and whether the first message is normal is determined based on a result of the comparison.

Abstract: A data reception apparatus calculates an integrated number of bits by integrating the number of bits in a received bit string; calculates an integrated number of samples by integrating the number of samples obtained by oversampling each bit; obtains a fitting line indicating correspondence between the integrated number of bits and the integrated number of samples based on a plurality of points of which each point corresponds to either only a rise edge or only a fall edge of each bit in the received bit string; and determines a bit length in the received bit string based on the fitting line.

Abstract: A communication system includes a communication wiring, at least one master node connected to the communication wiring, and at least one slave node connected to the communication wiring. The at least one master node and the at least one slave node are connected in a ring shape through the communication wiring and communicate in a start-stop synchronous communication.

Abstract: An edge interval measuring block measures a first same-edge interval. A bit number detector detects the number of bits in the first same-edge interval based on reference bit length information and detects a first number of bits in a same-value interval between consecutive bits of the same value by subtracting the number of bits in the known bit stream from the number of bits in the first same-edge interval. The edge interval measuring block then measures a second same-edge interval. The bit number detector detects the number of bits in the second same-edge interval based on the reference bit length information and detects a second number of bits in a bit stream of consecutive bits of the same value opposite to the value in the same-value interval by subtracting the first number of bits from the number of bits in the second same-edge interval.

Abstract: A data reception apparatus calculates an integrated number of bits by integrating the number of bits in a received bit string; calculates an integrated number of samples by integrating the number of samples obtained by oversampling each bit; obtains a fitting line indicating correspondence between the integrated number of bits and the integrated number of samples based on a plurality of points of which each point corresponds to either only a rise edge or only a fall edge of each bit in the received bit string; and determines a bit length in the received bit string based on the fitting line.

Abstract: An edge interval measuring block measures a first same-edge interval. A bit number detector detects the number of bits in the first same-edge interval based on reference bit length information and detects a first number of bits in a same-value interval between consecutive bits of the same value by subtracting the number of bits in the known bit stream from the number of bits in the first same-edge interval. The edge interval measuring block then measures a second same-edge interval. The bit number detector detects the number of bits in the second same-edge interval based on the reference bit length information and detects a second number of bits in a bit stream of consecutive bits of the same value opposite to the value in the same-value interval by subtracting the first number of bits from the number of bits in the second same-edge interval.