An apparatus for restricting a copy of digital information is provided with a
detecting device for detecting a first watermark, which is buried in the digital
information and comprises a first signal generated on the basis of a first rule.
A burying device buries a second watermark, which comprises a second signal generated
on the basis of a second rule and having a structure different from that of the
first signal, into the digital information if the first watermark is detected by
the detecting device. A recording apparatus is provided with: an inputting device
for inputting the digital information; the above mentioned copy restricting apparatus;
and a recording device for recording the digital information in which the second
watermark is buried by the burying device.