Patent ID: 7788271

Claim:
A content distribution server for distributing content to a plurality of terminals owned by a user, comprising: a content database for storing content identified by a content ID as a plurality of files, the plurality of files including different types of the same content and having a field, the types based on different attributes of the same content and assigned the same content ID, wherein a falsification detection value is stored in the field of the plurality of files; and a user database for storing, for each user identified by a user ID, a content ID of content purchased by the user; wherein, the content distribution server is configured to: receive a content purchase request, including a specified attribute of the requested content, and the user ID from a first terminal owned by the user, the specified attribute indicating one of the types of the same content, wherein the user is requesting to purchase a specified type of the same content; authenticate the first terminal on the basis of the received user ID; acquire the requested content, the content ID, and the falsification detection value from the content database after the request is received by using the specified attribute to identify the specified type for the acquisition from the plurality of files; store the acquired content ID and the received user ID in the user database by relating the acquired content ID with the received user ID; provide the requested content to the first terminal with information indicative of the received user ID; receive a content distribution request, including a specified attribute of the content requested for distribution, and the user ID from a second terminal owned by the user; authenticate the second terminal on the basis of the user ID received from the second terminal; acquire the content requested for distribution, from the content database, by using the content ID stored in the user database when the user ID received from the second terminal matches the user ID related to the content ID in the user database; and provide the content requested for distribution to the second terminal according to the attribute specified in the content distribution request and attaching the falsification detection value in a predetermined field of the content before providing the content, the attached falsification detection value detecting whether a group ID is associated with the user ID and identifying a service provided by the content distribution server when the second terminal attempts to process the provided content, wherein information indicative of the user ID received from the second terminal is provided with the content requested for distribution, and a type of the content requested for distribution is based on the attribute specified by the second terminal.