The key is necessary to build an HDMI sniffer, which involves special hardware. If all you have is a blu-ray drive and a blu-ray disk and a PC, it doesn't help

The key is necessary to build an HDMI sniffer, which involves special hardware. If all you have is a blu-ray drive and a blu-ray disk and a PC, it doesn't help you at all. Intel's usage of the word "affect" seems limited to "helps directly with copying".