On-board apparatus, abnormality detection method, and abnormality detection program

An abnormality detection method for an on-board apparatus that is to be mounted in a vehicle, comprising:

• a step of receiving, via a transmission path, a plurality of pieces of change information respectively indicating changes in measurement results of a plurality of sensors mounted in the vehicle;
• a step of performing delay processing for delaying and outputting at least one of the plurality of pieces of received change information;
• and
• a step of detecting an abnormality based on an internal output sequence that is an output sequence of the plurality of pieces of change information.

An abnormality detection program in an on-board apparatus to be mounted in a vehicle, the program being for causing a computer to function as:

• a receiving unit configured to receive, via a transmission path, a plurality of pieces of change information respectively indicating changes in measurement results of a plurality of sensors mounted in the vehicle;
• a delay processing unit configured to perform delay processing for delaying and outputting at least one of the plurality of pieces of change information received by the receiving unit;
• and
• a detection unit configured to detect an abnormality based on an internal output sequence that is an output sequence in which the delay processing unit outputs the plurality of pieces of change information.