Abstract: Map information distribution systems and methods store map information and version information for each road category of the map information stored in a navigation device, the version information correlated with identification information identifying the navigation device. The systems and methods receive the identification information from the navigation device and obtain, based on the received identification information, the version information for each road category of the map information stored in the navigation device corresponding to the stored identification information. The systems and methods extract, based on the obtained version information for each road category, differential data for each road category with stored map information of a latest version, and transmit the extracted differential data for each road category to the navigation device corresponding to the received identification information.

Abstract: A CPU of a navigation apparatus stores public keys to which priorities are set and which are published by an information distribution center in a public key storage section. The CPU of the navigation apparatus extracts an electronic signature of distribution data which is distributed from the information distribution center and verifies the electronic signature by using only ‘valid’ public keys among the public keys in order of the priorities. The CPU of the navigation apparatus determines that the distribution data is valid information which is distributed from the information distribution center when the electronic signature passes verification.

Abstract: Map information distribution systems, methods, and programs that update map information based and distribute the update information, send update request information for requesting the update information of the map information, receive the update request information, and obtain the update information corresponding to the received update request information. The systems, methods, and programs obtain updated content corresponding to the obtained update information, assign a score to the updated content based on factor information corresponding to the obtained updated content, assign an order of priority to the respective updated content based on the scores assigned to the respective updated content, distribute the update information and the prioritized updated content, update the map information based on the received update information, and notify a user of the received updated content based on the order of priority assigned to the updated content.

Abstract: A CPU of a navigation apparatus stores public keys to which priorities are set and which are published by an information distribution center in a public key storage section. The CPU of the navigation apparatus extracts an electronic signature of distribution data which is distributed from the information distribution center and verifies the electronic signature by using only ‘valid’ public keys among the public keys in order of the priorities. The CPU of the navigation apparatus determines that the distribution data is valid information which is distributed from the information distribution center when the electronic signature passes verification.

Abstract: Map information distribution systems and methods store map information and version information for each road category of the map information stored in a navigation device, the version information correlated with identification information identifying the navigation device. The systems and methods receive the identification information from the navigation device and obtain, based on the received identification information, the version information for each road category of the map information stored in the navigation device corresponding to the stored identification information. The systems and methods extract, based on the obtained version information for each road category, differential data for each road category with stored map information of a latest version, and transmit the extracted differential data for each road category to the navigation device corresponding to the received identification information.

Abstract: Map information distribution systems, methods, and programs that update map information based and distribute the update information, send update request information for requesting the update information of the map information, receive the update request information, and obtain the update information corresponding to the received update request information. The systems, methods, and programs obtain updated content corresponding to the obtained update information, assign a score to the updated content based on factor information corresponding to the obtained updated content, assign an order of priority to the respective updated content based on the scores assigned to the respective updated content, distribute the update information and the prioritized updated content, update the map information based on the received update information, and notify a user of the received updated content based on the order of priority assigned to the updated content.