We read a lot about the technologies drafted to protect copyrighted materials, but did you know that there are at least ten different methods for DVD? This very detailed report at ExtremeTech, delves into this world and helps us to understand the inner workings of these deterrents by describing each one and the reasoning behind its' conception. The second of a two part series, part one explores the history of copy-protection and intellectual property rights law and is an interesting read as well.
When the smoke cleared, DVDs had been crammed with more layers of copy protection than any other consumer format, and probably more acronyms too. Each of these is described in more detail later in this article. CSS: Pre-recorded DVD-Video content is encrypted by the Content Scrambling System (CSS) CPPM: the Content Protection for Prerecorded Media (CPPM) technology performs the same function for DVD-Audio material. Regional Playback Control: Prerecorded DVD-Video discs are also equipped with Regional Playback Control, which allows consumers to play movies only in their local geographic regions. CPRM: Writable DVD drives are prevented from indiscriminately copying protected content by the Content Protection for Recordable Media (CPRM) system. CGMS-A: The Macrovision DVD Copy Protection system, Copy Generation Management System (CGMS-A) Verance: The Verance DVD-Audio Watermarking technology guards analog output from being captured by analog and digital recorders DTCP: The Digital Transmission Content Protection (DTCP) system does the same for digital data streams. HDCP: DVI connections to digital monitors are protected by the High-bandwidth Digital Content Protection (HDCP) technology Video Watermarking: Although there's currently no way to guard against a pirate hijacking the VGA signal traveling between a PC and a monitor, the industry is working on a video-watermarking proposal that would prevent this and other types of vulnerabilities in the analog domain. CPSA: All these technologies are coordinated into a formal architecture, called the Content Protection System Architecture. Many of these technologies were circumvented shortly after their release, but that hasn't ended calls to add even more anti-piracy features. The justification for these continued efforts - a copy-protection scheme doesn't necessarily become ineffective when it's defeated by a determined cracker. Most are intended primarily to limit "casual copying," in which a consumer cavalierly runs off a quick duplication for a friend. |
Although lengthy, the article contains a lot of good information. They describe in as much detail as they felt prudent, the inner workings of each DVD copy-protection mechanism. They go on to say: To be considered successful, an anti-piracy scheme must be effective, difficult to defeat, and transparent to users. This material will help you decide how well today's DVD-protection tools meet these criteria.
Source: extremetech.com
