Data communication system, center device, master device, storage medium storing update data placement program, and storage medium storing update data acquisition program

A center device that places update data in a content delivery network (CDN), the center device comprising:

• a common key generation section that generates a common key for encrypting update data;
• an update data encryption section that encrypts the update data with the common key;
• a common key encryption section that encrypts the common key with an RSA public key;
• a common key storage section that stores the common key encrypted with the RSA public key in a campaign notification;
• a CDN vendor selection section that selects a CDN with a superior distribution cost from CDNs of a plurality of business operators according to at least one of a distribution method, a distribution area, a communication protocol, and a distribution data size;
• an encrypted data placement section that places the update data encrypted with the common key in the selected CDN;
• and
• a campaign notification transmission section that transmits a campaign notification in which the encrypted common key is stored to a vehicle-side system to be reprogrammed,
• wherein
• the CDN vendor selection section calculates a distribution cost for each CDN vendor based on a distribution data size and a distribution area of update data,
• the CDN vendor selection section determines whether the each CDN vendor is a CDN vendor that charges according to a total number of distribution requests, calculates a charge amount based on the number of requests for the CDN vendor that charges according to the number of distribution requests, and adds a charge amount based on a distribution data size to a charge amount based on the number of requests to select a CDN with a superior distribution cost.

A center device that places update data in a content delivery network (CDN), the center device comprising:

• a common key generation section that generates a common key for encrypting update data;
• an update data encryption section that encrypts the update data with the common key;
• a common key encryption section that encrypts the common key with an RSA public key;
• a common key storage section that stores the common key encrypted with the RSA public key in a campaign notification;
• a CDN vendor selection section that selects a CDN with a superior distribution cost from CDNs of a plurality of business operators according to at least one of a distribution method, a distribution area, a communication protocol, and a distribution data size;
• an encrypted data placement section that places the update data encrypted with the common key in the selected CDN;
• and
• a campaign notification transmission section that transmits a campaign notification in which the encrypted common key is stored to a vehicle-side system to be reprogrammed,
• wherein
• the CDN vendor selection section selects a CDN with a superior distribution cost from CDNs of a plurality of business operators based on a distribution data size and a distribution area of update data for a plurality of campaigns scheduled to be distributed for a predetermined period.

A non-transitory computer readable storage medium storing an update data placement program for causing a center device that places update data in a content delivery network (CDN) to execute:

• a common key generation step of generating a common key for encrypting update data;
• an update data encryption step of encrypting the update data with the common key;
• a common key encryption step of encrypting the common key with an RSA public key;
• a common key storage step of storing the common key encrypted with the RSA public key in a campaign notification;
• a CDN vendor selection step of selecting a CDN with a superior distribution cost from CDNs of a plurality of business operators according to at least one of a distribution method, a distribution area, a communication protocol, and a distribution data size;
• an encrypted data placement step of placing the update data encrypted with the common key in the selected CDN;
• and
• a campaign notification transmission step of transmitting a campaign notification in which the encrypted common key is stored to a vehicle-side system to be reprogrammed,
• wherein
• the CDN vendor selection step calculates a distribution cost for each CDN vendor based on a distribution data size and a distribution area of update data, determines whether the each CDN vendor is a CDN vendor that charges according to a total number of distribution requests, calculates a charge amount based on the number of requests for the CDN vendor that charges according to the number of distribution requests, and adds a charge amount based on a distribution data size to a charge amount based on the number of requests to select a CDN with a superior distribution cost.

A non-transitory computer readable storage medium storing an update data placement program for causing a center device that places update data in a content delivery network (CDN) to execute:

• a common key generation step of generating a common key for encrypting update data;
• an update data encryption step of encrypting the update data with the common key;
• a common key encryption step of encrypting the common key with an RSA public key;
• a common key storage step of storing the common key encrypted with the RSA public key in a campaign notification;
• a CDN vendor selection step of selecting a CDN with a superior distribution cost from CDNs of a plurality of business operators according to at least one of a distribution method, a distribution area, a communication protocol, and a distribution data size;
• an encrypted data placement step of placing the update data encrypted with the common key in the selected CDN;
• and
• a campaign notification transmission step of transmitting a campaign notification in which the encrypted common key is stored to a vehicle-side system to be reprogrammed,
• wherein
• the CDN vendor selection step selects a CDN with a superior distribution cost from CDNs of a plurality of business operators based on a distribution data size and a distribution area of update data for a plurality of campaigns scheduled to be distributed for a predetermined period.