To enable the control of rendering contents in part by using digital
watermark technique:
a contents serving center for embedding watermark in contents 4 embeds
control information as digital watermarks within at least one of a
plurality of blocks constituting electronic data by which contents are
represented, thereby specifying the application of filtering to a part of
the contents corresponding to the block; a contents distribution center 1
distributes the watermark-including contents to a receiving terminal 2
where checks the blocks of the received data to detect whether the control
information as digital watermarks is embedded therein and applies the
filtering to the block for which the embedded control information embedded
has been detected in advance of reproducing the contents.
