The CGMS unacceptable recorder accepts transmission frames only when the copyright protection information in a transmission header transmitted to the IEEE1394 serial bus indicates copy free. The CGMS acceptable recorder accepts transmission frames when the copyright protection information in the transmission header indicates copy free. When the copyright protection information in the transmission header indicates compliance with the copyright information contained in the content of the transmission frame, the copyright information in the content is fetched based on the signal format type information of the transmission header. As described herein above, a copy management information changeable apparatus such as a computer cannot accept data other than copy free signals from the digital interface.