updated 10:10 am EST, Tue November 18, 2008
HDCP on MacBooks
Certain movies bought through the iTunes Store appear to be taking advantage of the inherent copy protection hardware in the new MacBook lineup, a report from one Ars Technica reader. Attaching an external display without HDCP (High-bandwidth Digital Content Protection) encryption support, such as a projector with VGA-only input, produces a warning from some titles that the display isn't authorized to play protected movies and so refuses output.
The notice is inconsistent and appears for both new and titles such as Hellboy 2 and The Shawshank Redemption but doesn't always appear for these full-length titles. The locks also don't apply to TV shows, which historically haven't been copy-protected on regular digital TV channels.
Playback should be supported using Apple's LED CinemaDisplay, which supports HDCP by virtue of using DisplayPort, or through newer third-party displays with HDCP support over DVI by using a DisplayPort-to-DVI adapter. It should also work with HDTVs that either have similarly guarded DVI input or if a company develops a compatible DisplayPort-to-HDMI adapter.
While the DisplayPort format on the MacBook, MacBook Air, and MacBook Pro includes HDCP as part of its official spec, the previously unexpected notice confirms that Apple has implemented the 128-bit AES encryption as a complement to its FairPlay copy protection system. HDCP is most often used to prevent pirates from ripping Blu-ray or other digitally protected movies by capturing the raw video output but until now wasn't generally believed to be used by Apple.
The new MacBooks aren't the first devices to use HDCP from Apple, as the Apple TV uses it for relaying its signal over HDMI. However, the Apple TV also includes component video output that isn't subject to the same kind of restrictions. As DisplayPort is the only video output short of USB options on the company's portables, the move effectively pushes some owners to upgrade any external displays to newer models if they want to play iTunes movies.