To enhance illegal copy prevention strength of distributed contents in comparison with the conventional case without comparatively increasing a processing burden of the entire contents distribution system.

A user terminal 4 receives download files from the contents distribution system 2 and next, receives noise elimination data and distributing destination information (a step S11). Then, the user terminal 4 eliminates the noise from the respective download files by using the noise elimination data and obtains contents divided files (a step S12). Next, the user terminal 4 receives coupling data (a coupling key) from the contents distribution system 2 (a step S13) and obtains one contents file by coupling a group of the divided files by using the coupling data (a step S14). In addition, the user terminal 4 performs a write processing of the distributing destination information in parallel with processings in the steps S12 to S14 (a step S15).