Abstract: 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 function enabling copying of content are held in an authentication processing circuit (151) of a transmitter (10). When a model name obtained from a connected receiver (40) is held, regardless of whether the content is copyright protected, a signal selection circuit (122) selects a terminal a side, a switch (123) is turned on, and an unencrypted signal is transmitted. When a change of the receiver (40) is detected by a hot plug detection function or a plug and play function at a processing circuit (152) during the transfer of a signal of copyright protected content without providing copyright protection, the selection circuit (122) is made to select a terminal b side or the switch (123) 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.