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A primer on what HDCP is and how it can affect new Mac users (as well as those of us at ETC using new MacBooks with Crestrons).

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  1. 1. HDCP High-bandwidth Digital Content Protection
  2. 2. THE STORY HTTP://ARSTECHNICA.COM/APPLE/NEWS/2008/11/APPLE-BRINGS-HDCP-TO-A-NEW-ALUMINUM-MACBOOK-NEAR-YOU.ARS • Meet John: high school teacher • Purchased Hellboy II, wanted to watch it over lunch in his classroom • Hooked it up to his Prometheus system (Sanyo projector) via MiniDisplayPort-to-VGA adapter • Gotthe error message from iTunes when he tried to launch the movie
  3. 3. THE LOWDOWN • Most (but not all) iTunes Store movies have HDCP protection included • Examples of videos that don’t have it: Stargate: Continuum, Heroes Season 2 • Examples of those that do have it: Hellboy 2, Iron Man, some older films: Shawshank Redemption • In other words: it’s a toss-up
  4. 4. THE MONITORS • Using a MiniDisplayPort-to-DVI adaptor, MacWorld hooked up a MacBook to a LaCie monitor to play an iTunes Store movie: didn’t work • Same test on a HDCP-compliant ViewSonic display with HDMI port (using HDMI-to-DVI cable): works • Any display that’s HDCP-compliant you won’t have a problem with (or a receiver that’s HDCP-compliant) • Most new hi-def TVs & projectors are okay
  5. 5. SO WHY USE DISPLAYPORT OVER DVI OR HDMI? • Royalty-free (HDMI costs manufacturer 4¢ / device) • Lower power consumption than DVI • Offerscopy protection over transmitted content (DVI doesn’t)
  6. 6. THE NUTSHELL DVI GVIF UDI HDMI DisplayPort Unified Display Interface Digital Video Interface Gigabit Video Interface Hi-Def Multimedia Interface • Covers the 5 modern video-outs (first 3 are ubiquitous) • Digital copy protection from Intel • Prevents copying audio/video as it travels across the line • Even prevents copying when permitted by fair use laws
  7. 7. THE DETAILS • Proprietary specification; implementation requires license • In other words: you have to pay Intel yearly to put it in your products, or HDCP video won’t play with it • Certain terms & conditions apply • No HD protected video can be output to non-HDCP- compliant equipment • DVD-Audio restricted to CD-audio quality or less on non- HDCP-compliant output devices
  8. 8. THE TECHNO-JARGON • Purpose: to protect HD content during transmission • Three systems to achieve this goal: Authentication process prevents non-licensed displays from receiving • content Encryption of data sent over interface prevents eavesdropping, man-in-the- • middle attacks Key revocation ensures that compromised/cloned devices can’t receive data •
  9. 9. HOW IT WORKS • HDCP device has a confidential unique key set (40 keys, 56 bits each) • Keyselection vector (KSV) is special public key with 40 bits (once for each key), with some bits as 1, some as 0 • KSVs are exchanged, combined with secret keys, and a master 56-bit key is created for encryption (Blom’s scheme) • Each pixel is encrypted, each frame displayed updates keys
  10. 10. THE THREE DEVICES OF AN HDCP-PROTECTED SYSTEM include set-top boxes, DVD/Blu-Ray players, computer • Sources video cards (only has 1 HDCP/HDMI transmitter) render the content, such as TVs, digital projectors (1 or • Sinks more HDCP/HDMI transmitters) decrypt and re-encrypt content, may add signal • Repeaters processing; examples are A/V receivers
  11. 11. THE POLITICS • FCC approved HDCP in August 2004 • Struck-down ‘broadcast flag’ regulations would have required DRM on all digital outputs from HDTV signal demodulators • Legislation still making its way through Congress from FCC • HDCP required in the UK if a device is certified ‘HD’
  12. 12. WHAT HAS HDCP? • Really can’t buy HD-capable devices without it anymore • Blu-ray players • HDTVs • HDMI-enabled notebooks • TV
  13. 13. THE IMPLICATIONS • Apple uses Mini DisplayPort connectors on all new computers • Mac Pro, Mac mini also have full DVI ports • AnyHDCP-protected video from the iTunes Store won’t play on non-HDCP-compliant devices • Most HD content on the iTunes Store is affected • Since QuickTime 7.5.7, all standard-def (SD) content is okay