DVD and Blu- ray Copy Protection. This document discusses the technical and legal issues surrounding copy protection on DVD and Blu- ray discs. We are providing this information as a service and as a means of sharing our technical and legal knowledge. Nothing in this document, however, should be considered to be actual legal advice. It is for informational purposes only. Introduction to DVD and Blu- ray Copy Protection. Commercial pre- recorded DVD and Blu- ray discs are typically protected with some form of copy protection. There is, however, a great deal of confusion about how these copy protection schemes work and what kind of legal rights consumers may have. The purpose of this document is to clarify both the technical and the legal aspects of copy protection for DVD and Blu- ray discs. DVD Copy Protection. There are three types of copy protection that are used on commercial pre- recorded DVD discs. These are Analog Protection System (APS) scrambling, Content Scramble System (CSS) encryption, and a system involving corrupted disc structure. Recordable DVD discs are also sometimes copy protected using Content Protection for Recordable Media (CPRM) encryption. We will go over each of these schemes in turn. Analog Protection System (Macrovision)The Analog Protection System, popularly known as Macrovision after the company that developed it, is a protection system that is applied to the composite analog video signal coming out of DVD players. By manipulating the signal level of the composite video, Macrovision fools the automatic gain control of most video recorders resulting in annoying shifts in color and brightness in the recorded video. Macrovision can be defeated by passing the composite video signal through a hardware device that restores the proper video signal levels. With the demise of analog video and the widespread availability of digital decryption tools, Macrovision protection has largely become irrelevant. Macrovision Corporation renamed itself Rovi and now promotes other copy protection technologies. Further Reading. Content Scramble System (CSS) Encryption. CSS is an encryption system that is the main copy protection scheme used on pre- recorded DVD discs. CSS utilizes a proprietary 4. DVD disc. When the disc is inserted into a player or computer, a series of . In addition, many DVD drives will refuse to complete the . Both of these situations can cause strange behavior and odd error messages on computer systems. Further Reading. DVD Disc Corruption. For a CPRM encoded disk to be. Review of top best free DVD and Blu-ray ripper for Windows XP, Vista, 7, and 8. DVDFab HD Decrypter vs BDlot DVD ISO Master vs WinX DVD Ripper vs Handbrake. In this free DVD rippers review, 11 best free DVD rippers are listed. B'z blog BUCK-TICK DEAD END dokken Gary Moore GOD BLESS YOU hide INORAN J LEGO LUNA SEA MICHAEL JACKSON Plastic Tree Queen ROSIER SHAZNA SONY SUGIZO Tourbillon van halen WA1 wii X YouTube. After the CSS protection system was cracked, the movie industry looked for a alternative copy protection scheme that would be compatible with the large number of existing DVD players in the marketplace. Borrowing a (failed) technique from the video game industry, they settled on a scheme in which portions of DVD discs are deliberately mangled in such a way as to render them unreadable. When the disc is played, these corrupted areas of the disc are skipped. When the disc is copied sequentially, however, these corrupted areas cause the drive to hang up and get stuck. This copy protection scheme has been marketed under a variety of names, including ARcc. OS (by Sony), Rip. Guard (by Rovi), Disney X (by Disney), etc. For cost and convenience reasons, it is not applied to all commercial DVD releases. DVD disc corruption is a nuisance, but most of the more sophisticated DVD copy tools can handle it. Some tools maintain a database of corrupted areas on DVD discs that contain corruption, while other tools attempt to analyze the DVD structure to find areas of the disc that are never accessed. Further Reading. Content Protection for Recordable Media (CPRM)CPRM is a copy protection scheme that is used for Secure Digital (SD) memory cards and recordable DVD discs, including DVD- R, DVD+R, DVD- RW, and DVD+RW discs. Special CPRM- compatible recordable media are required, with each disc including a unique Media ID inscribed as a bar code in the inner hub area. When a CPRM- compliant recorder detects compatible media, it uses the unique Media ID on the disc to encrypt the data it records to the disc. The recorder will also write a block of data called the Media Key Block (MKB) which is used to decrypt the disc. If the disc is copied, the Media ID on the new disc will be different and the recorded data will not decrypt correctly. CPRM protection has largely been restricted to the Japanese market, where it is called . Japanese- market recorders that record that program are required to include CPRM protection. Depending on the Copy Guard instructions, a limited number of copies of the CPRM disc data may be permitted. The CPRM system involves something called the Cryptomeria or C2 cipher, which uses a 5. The majority of the cipher is published openly, but a proprietary . The licensing organization is called the 4. C Entity, whose membership includes IBM, Intel, Microsoft, Panasonic and Toshiba. A cryptanalysis of the C2 cipher was published in 2. CPRM was partially cracked in late 2. Windows based on the key from this crack was distributed over the internet. Further Reading. Blu- ray Disc Copy Protection. The Blu- ray Disc standard mandates that all pre- recorded discs be protected by a copy- protection scheme. The copy protection used on pre- recorded discs is in practice only applied to the stream files and not to any other files that make up the format. There are several distinct levels of copy protection for pre- recorded discs. AACS Encryption. The first level of copy protection applied to pre- recorded discs is the Advanced Access Content System (AACS) developed by the AACS Licensing Administrator, a consortium of companies including Disney, Intel, Microsoft, Panasonic, Warner Bros., IBM, Toshiba and Sony. It is based on Advanced Encryption Standard (AES), a robust 1. US government. AACS includes a system by which the keys assigned to a particular player can be . When a newer Blu- ray disc is inserted into an older drive, the drive is required to check the version of the . Thus playing newer discs propagates the revoked key lists out to all drives. AACS was broken beginning in late 2. AACS decryption programs are available online. The key revocation system ensures, however, that the AACS licensing organization and the hacker community are constantly playing a cat- and- mouse game. Further Reading. BD+ Protection. BD+ is a second level of copy protection that is optional for pre- recorded Blu- ray discs. After the stream files are encrypted using AACS encryption, they are further mangled randomly with instructions on how to repair the mangled files stored on the disc as special BD+ instructions. These instructions run in something called a . The virtual machine on the player runs the BD+ code on the disc and retrieves something called the . Each new BD+ Blu- ray disc release brings new twists in the virtual machine programs, each of which are again reverse- engineered by the hacker community. Just as with AACS, BD+ has become a cat- and- mouse game. Currently, the BD+ system is owned by Irdeto, which bought it from Rovi Corporation in 2. Further Reading. Cinavia Protection. Cinavia, developed by a company called Verance, is a newer level of copy protection that is optional on Blu- ray discs. Verance claims the Cinavia signal is inaudible, and that the signal can survive audio compression and recompression. When a player with Cinavia support detects a Cinavia signal on a Blu- ray disc, it can verify whether playback should be allowed. The player can display one of four possible messages known as . The most commonly viewed messages are (1) . Message (1) is supposed to stop distribution of . Message (3) is supposed to stop unencrypted ripped copies of movies. There is apparently no exception for consumer backup copies. Cinavia detection became a requirement for Blu- ray players beginning in 2. To date, the only major studio that appears to be using Cinavia is Sony Pictures, and that is not even for all releases. Most of the major studios seem to be hesitant about including Cinavia protection, perhaps because the system involves expensive royalty fees, or perhaps for fear of angering customers. Customers have a reason to be angry, because unlike all the other protection schemes on Blu- ray and DVD discs, Cinavia protection is destructive and permanent. Audio tracks that include Cinavia have been deliberately damaged, and the damaged audio is present both for legimitate customers and for the supposed content pirates. When the audio track is protected with Cinavia, legitimate customers do not get the pristine audio content they paid for on their Blu- ray discs. The Cinavia encoding system was broken in 2. One ripper tool company claims to be able to do this, but their success rate is apparently spotty. Other ripper tool companies have figured out schemes to disable or fool Cinavia detection in players. Some stand- alone players (e. Panasonic, Oppo) have firmware patches available to remove Cinavia detection. Further Reading. Removing DVD and Blu- ray Copy Protection. The removal of copy- protection schemes from DVD and Blu- ray discs involves both legal issues and technical issues. On the legal side, efforts by the movie industry have made defeating copy protection a bit of a legal gray area. On the technical side, ripping programs are widely available, but efforts by the movie industry have made them into essentially subscription services. Each update to the copy protection schemes results in an update to the ripper programs. Legal Issues. In the US, a controversial law called the Digital Millennium Copyright Act (DMCA) has criminalized any attempt to decrypt protected content, even if the consumer has legally purchased the content. The problem is that this . The courts have yet to rule on which portion of the law should prevail. Because of this legal uncertainly, it is legally risky for any software company to market DVD or Blu- ray disc- related tools that include decryption capabilities.
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