Patent ID: 7054929

Claim:
A communication system for communicating information between network sites that are connected to each other via a network, the system comprising: a first network site of a first entity that has a pre-established trusted relationship with the a user the first network site including a diagnosis unit performing a diagnosis of the user, who uses a terminal device on the network, a memory unit storing private information of the user and a diagnosis result of the diagnosis unit together in association with an ID key, an issue unit for issuing the ID key corresponding to the diagnosis result, the ID key being issued by the first network site and being used by a second network site of a second entity as a key for obtaining the private information of the user from the first network site, where the second entity does not have a trusted relationship with the user, a first transmission unit transmitting the diagnosis result and the ID key to the user, and a second transmission unit transmitting the private information and the diagnosis result to the second network site; and the second network site including an ID key reception unit receiving the ID key from the user, an ID key transmission unit transmitting the ID key received by the ID key reception unit to the first network site, and a user information reception unit receiving the private information corresponding to the ID key transmitted to the first network site and the diagnosis result from the first network site; wherein the second transmission unit transmits the private information corresponding to the ID key indicated by the second network site and the diagnosis result.