A source device and a method of transmitting content are provided. The source device includes a controller configured to check a version of a content protection method supported by a sink device from the repeater, to encrypt the content based on a version of the content protection method applied to the content, and to set a value of type information of the content protection method based on the version of the content protection method applied to the content and the version of the content protection method supported by the sink device, and a communicator including communication circuitry configured to transmit the encrypted content and the type information of the content protection method to the repeater, wherein the type information of the content protection method for determining whether the content received from the source device is output to the sink device from the repeater, based on the version of the content protection method supported by the sink device.