Method for preventing identity theft for a specific electronic control unit of a motor vehicle

A method for preventing identity theft for a specific electronic control unit of a motor vehicle, when the specific electronic control unit sends a plaintext message which contains measurement data to a central electronic control unit of the motor vehicle, the central electronic control unit comprising at least one database that stores at least one tuple of values formed by an identifier for selecting a hashing algorithm and a hashing algorithm, the method comprising, when implemented on the specific electronic control unit:

• generating an identifier for selecting a hashing algorithm;
• acquiring at least one evolutive parameter common to the central electronic control unit and the specific electronic control unit;
• generating a first digital hashing fingerprint of the combination of the plaintext message and of the common parameter, from the identifier for selecting the hashing algorithm;
• forming a data frame that includes the plaintext message, the identifier for selecting a hashing algorithm and the first digital hashing fingerprint;
• and
• sending the data frame to the central electronic control unit.