Patent ID: 11895127
Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 4:
5. A method of determining a communication abnormality, comprising:
receiving a plurality of first data and a plurality of second data respectively corresponding to each of the plurality of first data;
generating a plurality of third data based on each of the received plurality of first data and an encryption key;
collecting a group of the plurality of second data received within a predetermined amount of time after start-up of a vehicle;
comparing each of the group of the plurality of second data received within the predetermined amount of time after the start-up of the vehicle and a corresponding third data of the plurality of third data to authenticate a corresponding first data of the plurality of first data; and
as a result of the comparisons between each of the group of the plurality of second data received within the predetermined amount of time after the start-up of the vehicle and the corresponding third data:
determining that a device is in an abnormal state if all of the comparisons do not match,
determining that the device is an attacked state if a part less than all of the comparisons do not match, and
determining that the device is in a normal state if all of the comparisons do match, wherein

the abnormal state is not the attacked state, and
the abnormal state is a state indicating that there is a failure in a communication function of the device or a state indicating an abnormality where the encryption keys do not match.