Method and system for preventing simultaneous use of contents in different formats derived from the same content at a plurality of places

An information processing system for processing contents, comprising:

• a first storage device;
• a second storage device;
• and
• a controller, wherein:
• the first storage device includes a first storage area in which the contents are recorded, and a second storage area limited for access;
• a first encrypted content obtained by encrypting a first content by using a predetermined encryption key, and a second encrypted content obtained by encrypting a second content, which is generated by executing a predetermined conversion process for the first content, by the encryption key used for encrypting the first content are recorded in the first storage area;
• first license information regarding the first content and the second content is recorded in the second storage area;
• the second encrypted content is recorded in the second storage device;
• the first license information containing use period information indicating a use period to permit use of one of the first content and the second content, and an encryption key for decrypting the first encrypted content and the second encrypted content;
• the controller transmits the obtained use period to the first storage device upon acquisition of the use period of the second content;
• the first storage device generates second license information which is a copy of the first license information, changes use period information contained in one of the first license information and the second license information to the transmitted use period, transmits license information containing the changed use period information to the controller, and deletes the use period contained in the transmitted license information from use period information contained in the other of the first license information and the second license information;
• and
• the controller transmits the license information transmitted from the first storage device to the second storage device.

An information processing terminal, which is connected to a storage device for recording contents, comprising a controller, wherein:

• a first encrypted content obtained by encrypting a first content by using a predetermined encryption key, a second encrypted content obtained by encrypting a second content, which is generated by executing a predetermined conversion process for the first content, by the encryption key used for encrypting the first content, and first license information regarding the first content and the second content are recorded in the storage device;
• the first license information contains use period information indicating a use period to permit use of one of the first content and the second content, and an encryption key for decrypting the first encrypted content and the second encrypted content;
• the first content and the second content are identified by content identifiers;
• conversion information is added to each of the content identifiers;
• the content identifier for identifying the second content is equal in value to the content identifier for identifying the first content;
• the conversion information added to the content identifier for identifying the second content contains a value indicating whether the second content has been generated by executing the predetermined conversion process;
• and
• the controller is configured to:
• obtain the content identifier to which the conversion information has been added from an application;
• judge whether the content identified by the content identifier to which the conversion information has been added is the second content based on the conversion information;
• obtain a use period of the second content via the application when the content identified by the content identifier to which the conversion information has been added is judged to be the second content;
• and
• transmit the obtained use period to the storage device.

A method of controlling an information processing system for processing contents,

• the information processing system comprising:
• a first storage device;
• and a controller,
• the first storage device including a first storage area in which the contents are recorded, and a second storage area limited for access,
• a first encrypted content obtained by encrypting a first content by using a predetermined encryption key being recorded in the first storage area,
• a second encrypted content obtained by encrypting a second content, which is generated by executing a predetermined conversion process for the first content, by the encryption key used for encrypting the first content being recorded in the first storage area,
• first license information regarding the first content and the second content being recorded in the second storage area,
• the first license information containing use period information indicating a use period to permit use of one of the first content and the second content, and an encryption key for decrypting the first encrypted content and the second encrypted content,
• the method comprising:
• generating, when the first storage device obtains the use period of the second content from the controller, second license information which is a copy of the first license information;
• changing use period information contained in one of the first license information and the second license information to the obtained use period;
• transmitting license information containing the changed use period information from the first storage device to the controller;
• and
• deleting the use period contained in the transmitted license information from use period information contained in the other of the first license information and the second license information.