To enable usage of content at a receiver which does not have a copying function even if copyright protection is provided. Model names of receivers not having a copying funtion are held in an authentication processing circuit of a transmitter. When a model name obtained from a connected receiver is held, regardless of whether the content is copyright protected, a signal selection circuit selects a terminal a side, a switch is turned on, and an unencrypted signal is transmitted. When a change of the receiver is detected by a hot plug detection or plug and play function at a processing circuit during the signal transfer of copyright protected content without providing copyright protection, the selection circuit selects a terminal b side or the switch is turned off to suspend the transfer of the non-copyright protected signal. The information indicating the receiver is held in a tamper-proof updateable manner.