Vehicle system and key distribution method

1. A vehicle system comprising:

a plurality of electronic control devices respectively includes a first processor configured to control each unit of a vehicle; and

a management electronic control device that includes a second processor configured to manage the plurality of electronic control devices, wherein

when an encryption key used to verify a message is updated to another encryption key, the second processor transmits a first message that includes a controller area network identifier (CAN-ID) that identifies the message and a second message that includes the another encryption key to a network, and

when the CAN-ID of the message included in the first message is a CAN-ID to be processed, the first processor updates the encryption key used to verify the message to the another encryption key included in the second message.

2. The vehicle system according to claim 1 , wherein

when requesting to update the encryption key used to verify the message, a first electronic control device of the plurality of electronic control devices transmits a third message including the CAN-ID for identifying the message to the network.

3. The vehicle system according to claim 1 ,

wherein the second processor is configured to generate the another encryption key when a predetermined period has elapsed from a generation time of the encryption key.

4. The vehicle system according to claim 1 ,

wherein the first message includes an unique identifier (UID) assigned to a target electronic control device that updates the encryption key, and a slot where the encryption key is stored.

5. The vehicle system according to claim 4 ,

wherein the first processor included in an electronic control device of the plurality of electronic control devices is configured to acquire the second message when the UID included in the first message matches with the UID assigned to the electronic control device.

6. The vehicle system according to claim 1 ,

wherein the second message includes counter value for preventing a replay.

7. A key distribution method executed by a vehicle system that includes a plurality of electronic control devices used to control each unit of a vehicle and a management electronic control device configured to manage the plurality of electronic control devices, the key distribution method comprising:

when an encryption key used to verify a message is updated to another encryption key, transmitting, by a second processor included in the management electronic control device, a first message including a controller area network identifier (CAN-ID) that identifies the message and a second message that includes the another encryption key; and

when the CAN-ID of the message included in the first message is a CAN-ID to be processed, updating, by a first processor included in at least one of the plurality of electronic control devices, the encryption key used to verify the message to the another encryption key included in the second message.

8. The key distribution method according to claim 7 , further comprising

generating, by the second processor, the another encryption key when a predetermined period has elapsed from a generation time of the encryption key.

9. The key distribution method according to claim 7 ,

wherein the first message includes an unique identifier (UID) assigned to a target electronic control device that updates the encryption key, and a slot where the encryption key is stored.

10. The key distribution method according to claim 7 ,

wherein the second message includes counter value for preventing a replay.