SECURITY MEASURE METHOD AND SECURITY MEASURE SYSTEM

A security measure method for software executed by a vehicle is provided. The software is implemented by a plurality of first modules. The vehicle includes a ROM configured to store a plurality of second modules corresponding to the plurality of first modules. The vehicle checks whether or not there is an abnormality in each of the plurality of first modules, extracts, when an abnormal first module is detected, the abnormal first module from the software, reads the second module corresponding to the abnormal first module from the ROM, and rewrites the abnormal first module in the software to the second module read from the ROM.