Encryption key distribution system, key distribution ECU, key reception ECU, key distribution program, key reception program, and encryption key distribution method

摘要

An encryption key distribution system that can reduce the amount of data required for key update is provided. In an encryption key distribution system (1) having a key distribution ECU (100) that transmits an encryption key and a key reception ECU (200) that receives the encryption key, the key distribution ECU transmits the encryption key to the key reception ECU. (133). In addition, the key distribution ECU determines whether the verification data transmitted from the key receiving ECU matches the verification data of the encryption key calculated from the common key held in the own device and the identifier of the key receiving ECU. Based on the result, the completion of transmission of the encryption key to the key receiving ECU is determined (134). The key receiving ECU records the received encryption key in its own device, calculates verification data of the received encryption key from the common key held in the own device and the identifier of the own device, and transmits it to the key distribution ECU. (231).