For Mac OS X, what is required for HDCP (video copy-protection) on an external monitor with HDMI?

I have a (non-Retina) MacBook Pro (mid-2012) and I have just purchased an Asus VN248H-P external monitor with HDMI input, connected to the MacBook Pro with a Monoprice Mini-DisplayPort to HDMI cable . This is not a television set; it is a peripheral computer monitor. For the first time, I tried to play a movie purchased and downloaded from iTunes on the external monitor, and I got an error message in iTunes saying that this is not supported because the Mac cannot verify HDCP support for my configuration. (This refers to the High-bandwidth Digital Content Protection encryption scheme ). > The selected movie won't play on one of your connected displays. > > This movie can be played only on displays that support HDCP (High-bandwidth Digital Content Protection). > > Try moving the iTunes window to a different display. Make sure the entire window is on the supported display. iTunes will only let me play the movie on the built-in screen on my (non-Retina) MacBook Pro, which is smaller and lower-resolution. Is my Monoprice cable incompatible, and do I need to replace it with a different cable or adapter? Is there such a thing as a cable or adapter that works with HDCP and will enable this? Or is playing HDCP-encrypted content simply not possible on my configuration? Please don't give me an answer that involves using software to break the HDCP encryption or to transcode to a different video format; I'd like to know if there is a hardware solution for full compatibility so that I don't lose any video resolution by transcoding.