What is HDCP?

This is some explanation of the DRM problem from wikipedia:

High-bandwidth Digital Content Protection (HDCP) is a form of Digital Rights Management (DRM) developed by Intel Corporation [Ah Mah Gad!!!] to control digital audio and video content as it travels across Digital Visual Interface (DVI) or High-Definition Multimedia Interface (HDMI) connections. The specification is proprietary, and creating an implementation of HDCP requires a license. [Dif3aw ya manufacturers!]

In addition to paying fees, licensees agree to limit the capabilities of their products. For example, high-definition digital video content must be restricted to DVD quality on non-HDCP compliant video outputs when requested by the source. [Shil faida HD?!]

Licensees cannot allow their devices to make copies of content, and must design their products to "effectively frustrate attempts to defeat the content protection requirements." ['7air inshallah]

Specs:

- Authentication process disallows non-licensed devices to receive HD content. [lazim tifilsif]
- Encryption of the actual data sent over DVI or HDMI interface prevents eavesdropping of information. It also prevents "man in the middle" attacks. [tashfeer ma lah da3i]
- Key revocation procedures ensure that devices manufactured by any vendors who violate the license agreement could be relatively easily blocked from receiving HD data. [ya3ni black-listing your device o roo7 saw update]

The details:

Each HDCP capable device model has a unique set of keys; there are 40 keys, each 56 bits long. These keys are confidential and failure to keep them secret may be seen as a violation of the license agreement. For each set of keys a special key called a KSV (Key Selection Vector) is created. Each KSV has exactly 20 bits set to 0 and 20 bits set to 1.

During the authentication process, both parties exchange their KSVs. Then each device adds (without overflow) its own secret keys together according to a KSV received from another device. If a particular bit in the vector is set to 1, then the corresponding secret key is used in the addition, otherwise it is ignored. Keys and KSVs are generated in such a way that during this process both devices get the same 56 bit number as a result. That number is later used in the encryption process.

Uses:

HD DVD, Blu-ray Disc and DVD players (with HDMI or DVI connector) use HDCP to establish an encrypted digital connection. If the display device—or in the case of using a PC to decrypt and play back HD-DVD or Blu-ray media, the graphics card (hardware, drivers and playback software)—does not support HDCP, then a connection cannot be established.

Windows Vista, utilizes this technology in the context of computer graphics cards and monitors. [ee Microsoft!]

By 2005, HDCP filtering devices were developed and freely sold in countries without restrictions on circumventing DRM. Those usually take the form of filters that have to be installed in the signal path between the movie player or decoder and the TV. The devices strip HDCP information out of the video signal, leaving the movie playable on non-HDCP displays. [bu6 feekom]