Patent ID: 7461255

Claim:
A system having a server and a terminal in communication with each other for embedding a digital watermark in content, wherein the server comprises: a segmentation unit configured to segment the content into a plurality of partial contents; a watermarking unit configured to embed a digital watermark in at least one partial content segmented in said segmentation unit to obtain a watermarked partial content; a primary encryption unit configured to primarily encrypt the watermarked partial content to obtain a primarily encrypted partial content; a first transmission unit configured to transmit the primarily encrypted partial content, and other partial contents in which a watermark is not embedded in said watermarking unit, to the terminal; a primary decryption unit configured to primarily decrypt double encrypted partial content transmitted from the terminal to obtain secondarily encrypted partial content; and a second transmission unit configured to transmit the secondarily encrypted partial content to the terminal, and the terminal comprises: a secondary encryption unit configured to secondarily encrypt the primarily encrypted partial content to obtain the double encrypted partial content; a third transmission unit configured to transmit the double encrypted partial content to the server; a secondary decryption unit configured to secondarily decrypt the secondarily encrypted partial content to generate watermarked plain partial content in which the digital watermark is embedded and which is not encrypted; and a synthesis unit configured to synthesize the watermarked plain partial content generated by said secondary decryption unit and other partial contents transmitted from the server by the first transmission unit.