CONTENT USAGE AUTHORITY MANAGEMENT SYSTEM AND MANAGEMENT METHOD

摘要

A system eliminating user content usage authority management at the service provider side and capable of upgrading the content usage condition. An encrypted content is delivered and only a valid user is allowed to use the content. The service provider receives a content usage authority certificate from a user. When a digital signature of an issuing entity of the content usage authority certificate shows that the data has not been altered, the user information and the user content purchase information are acquired from the content usage authority certificate and an upgrading processing such as a usage condition is performed. Thus, it is possible to perform content usage condition modification and the like without holding the user management data at the service provider side.