A source device for transmitting content to a sink device is provided. The source device may include an interface configured to perform high-bandwidth digital content protection (HDCP) authentication with the sink device, and a controller configured to determine an HDCP version supported by the sink device, convert the content so as to be encrypted in the HDCP version supported by the sink device in response to a determination that another HDCP version applied to the content is not supported by the sink device, encrypt the converted content in the HDCP version supported by the sink device, and control the interface to transmit the content to the sink device.