Despite a recession that began in 2008 and a subsequent slow recovery both in the United States and abroad, the Blu-ray DVD player has managed to survive and even thrive among videophiles. Admittedly, at Blu-ray’s inception there were many critics who did not believe moviegoers would pay $30.00 for a DVD. However, movie companies have won over the hearts and minds of avid home movie viewers by delivering what was promised Blu-ray would beâ€¦the absolute best and most state-of-the-art movie image and sound that could possibly be delivered in a home format.
With James Cameron’s Avatar becoming the most successful Blu-ray DVD to date, Blu-ray manufacturers could finally breath a sigh of relief and be confident that the once infant format has finally matured. The next dilemma facing Blu-ray is an old problem that once again reared its ugly ahead to threaten this newbie format. It’s a problem that Hollywood filmmakers are all too familiar with. The potential loss of revenue as well as reputation that comes from illegal duplication of DVD’s.
The problem of illegal copies of movies released onto home formats dates back as as the first years Beta and VHS movies were available. Several copy protection ideas were tried over the years including one-night rentals in which customers were required to return movies the following day to video stores to cut down on the time the customer would have to make duplications. Many movie companies began to use Macrovision in the later 1980’s which would produce a completely scrambled picture to whomever attempted to make an illiegal bootleg of a prerecorded video tape. Illegal videotape duplication provided one set of problems for filmmakers, but the world of DVD is a completely different universe. Now with software readily available over the Internet that can make exact copies of DVD movies, Hollywood had to rethink their strategy.
The Advanced Access Content Systems (AACS) is a standard for content Distribution and digital rights management. It was developed by AS Licensing Administrator, LLC (AACS LA), a consortium that includes Disney, Intel, Microsoft, Panasonic, Warner Bros., IBM, Toshiba, and Sony.
Since appearing in devices in 2006, several successful attacks have been made on the format. The first known attack relied on the trusted client problem. In addition, decryption keys have been extracted from a weakly protected player (WinDVD). Since keys can be revoked in newer releases, this is only a temporary attack, and new keys must continually be discovered in order to decrypt the latest discs. This cat-and-mouse game has gone through several cycles.
BD+ was developed by Cryptography Reseacrh Inc. and is based on their concept of Self-Protecting Digital Content. BD+ effectively a small virtual machine embedded in authorized players, allows content providers to include executable programs on Blu-ray Discs. Such programs can: examine the host environment to see if the player has been tampered with. Every licensed playback device manufacturer must provide the BD+ licensing authority with memory footprints that identify their devices. BD+ can also verify that the player’s key have not been changed as well as execute native code, possibly to patch an otherwise insecure system. Parts of the content will not be viewable without letting the BD+ program unscramble it.
If a playback device manufacturer finds that its devices have been hacked, it can potentially release BD+ code that detects and circumvents the vulnerability. These programs can then be included in all new content releases.
The specifications of the BD+ virtual machine are available only to licensed device manufacturers. The first titles using BD+ were released on October 2007. Versions of BD+ protection have been circumvented by various Versions of the AnyDVD HD program. Another program known to be capable of circumventing BD+ protection is DumpHD.