Patent ID: 11876898
Assignee: DENSO CORPORATION
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 10:
11. A data structure of rewrite specification data for program update stored in a non-transitory storage medium of a vehicle master device the vehicle master device comprising a data communication module that is mounted in a vehicle and configured to receive update data and the rewrite specification data from outside of the vehicle via a wireless communication network and a central gateway that is mounted in the vehicle, the central gateway includes one or more computers,
the data structure of the rewrite specification data including device identification information for identifying a rewrite target electronic control unit of a plurality of electronic control units and a key derivation value corresponding to the device identification information,
the data communication module communicating the rewrite specification data and the update data to the central gateway via a first communication bus inside of the vehicle;
the central gateway communicating the update data to a rewrite target electronic control unit of a plurality of electronic control units via a second communication bus inside of the vehicle, and
the one or more computers of the central gateway being programmed to:
acquire the rewrite specification data each time one of the plurality of electronic control units is updated either at the same time as acquisition of the update data or prior to acquisition of the update data;
analyze the rewrite specification data;
store a plurality of decryption keys for generation of corresponding security access keys, the security access keys used to perform device authentication of the plurality of electronic control units, the stored plurality of decryption keys being unreadable from outside of the central gateway and each decryption key of the stored plurality of decryption keys corresponding to a respective electronic control unit of the plurality of electronic control units;
extract the key derivation value corresponding to the rewrite target electronic control unit from an analysis result of the rewrite specification data, the key derivation value being generated outside of the vehicle;
select a decryption key corresponding to the rewrite target electronic control unit from the stored plurality of decryption keys;
decrypt the extracted key derivation value using the selected decryption key;
generate a security access key based on the decrypted extracted key derivation value; and
authenticate the rewrite target electronic control unit using the security access key; wherein after successful authentication of the rewrite target electronic control unit with the security access key, the central gateway distributes the update data to the rewrite target electronic control unit and instructs the rewrite target electronic control unit to rewrite a program.