Data terminal equipment

摘要

A data terminal equipment (3a) retrieves index data (Didx) indicating content data ( Dcnt ). Then, the data terminal equipment (3a) authenticates the content data ( Dcnt ) based on the index data ( Didx ). Only if the authenticity of the content data ( Dcnt ) has been confirmed, the data terminal equipment (3a) retrieves the content data ( Dcnt ) from a first server (1).