Content distribution system

A content distribution system comprising:

• a data processing apparatus of a content transmitter that transmits a content;
• a data processing apparatus of a user that receives the content;
• a data processing apparatus of a third party trusted by both the content transmitter and the user;
• and
• a communications network connecting the data processing apparatuses of the content transmitter, the user and the third party for mutual data communication;
• wherein the data processing apparatus of the content transmitter supplies a cipher to the data processing apparatus of the user;
• wherein the data processing apparatus of the user is provided with a tamper-resistant device storing data inaccessible from outside;
• wherein the data processing apparatus of the third party transmits first data to the data processing apparatus of the user, the first data relating to an encryption key that decodes the cipher, the encryption key being obtained only within the tamper-resistant device;
• and
• wherein the tamper-resistant device decodes the cipher by using the first data from the data processing apparatus of the third party.

A tamper-resistant device used in a content distribution system, the system comprising a data processing apparatus of a content transmitter to supply an encrypted content, a data processing apparatus of a user to receive the supplied content, a data processing apparatus of a third party which is trusted by both the content transmitter and the user and supplies data on a key to decode the encrypted content, and a communications network connecting the respective data processing apparatuses to each other for mutual data communication, the tamper-resistant device comprising:

• a memory storing data inaccessible from outside;
• a key obtainer that restores the decoding key based on the key data supplied from the data processing apparatus of the third party;
• and
• a decoder that decodes the encrypted content by using the decoding key restored by the key obtainer.

A content distribution process performed in a system that comprises a data processing apparatus of a user to receive an encrypted content supplied from a content transmitter, a data processing apparatus of a third party trusted by both the content transmitter and the user, and a communications network connecting the data processing apparatuses of the user and the third party for mutual data communication, the content distribution process comprising the steps of:

• causing the data processing apparatus of the user to issue an instruction to the data processing apparatus of the third party for carrying out a procedure to make a payment for the content;
• causing the data processing apparatus of the third party to send first data to the data processing apparatus of the user when the payment for the content is made from an account of the user to an account of the third party, the first data serving to provides a key that decodes the encrypted content, the decoding key being available only within the data processing apparatus of the user;
• and
• causing the data processing apparatus of the user to decode the encrypted content using the first data supplied from the data processing apparatus of the third party.