Movie studios and software companies fought to maintain (and crack) the efficacy of Blu-ray's BD+ DRM scheme throughout all of 2008, but the content industry has won a round of its own as the year draws to a close. Thanks to an update in late November, there's a growing list of movies Slysoft's AnyDVD HD product can't yet handle; the software company believes it could take three months or more to recrack the algorithm.

The back-and-forth cracking war officially began last March when Slysoft announced that it had cracked the BD+ algorithm and would include Blu-ray backup support in AnyDVD HD 6.4.0.0. At the time, Slysoft poked fun at the notion that BD+ would remain unbroken for any length of time, and noted that it had been just eight months since Richard Doherty of the Envisioneering Group had predicted BD+ would remain unbreached for the next decade. The company's hubris may have been premature, as BD+ is putting up something of a fight.

Slysoft breached BD+, beta support for Blu-ray disc backup was unofficially included in AnyDVD HD betas months before it formally launched last March, but certain aspects of the standard make it considerably more resilient than the copy protection schemes that came before it. Unlike AACS (Advanced Access Control System, used in both Blu-ray and HD DVD) or CSS (Content Control System, used on DVD), BD+ was designed to allow for periodic updates that could resecure protected content in the event of a breach.

Movie studios have gone several rounds with Slysoft since the company first announced its initial breakthrough. When the movie Jumper was released to Blu-ray on June 10, it included an updated version of BD+ that temporarily stymied Slysoft's crack. In this case, temporarily is the key word; AnyDVD 6.4.5.0 hit the streets just seven days later with updated BD+ support. Jumper remained safely ensconced for all of a week.

Big Content's November update appears to have done a more thorough job of closing current loopholes. Slysoft still anticipates that it will be able to break the updated scheme, but, as previously mentioned, believes it'll take about three months, versus the seven-day window we saw last June.

The fact that BD+ can be resecured, even temporarily, raises a host of questions regarding the future of content distribution. It's generally understood that the point of DRM is to make content theft difficult, rather than permanently impossible, and a DRM scheme that is periodically updated is a more difficult target for companies like Slysoft to hit. Using a dynamic system changes the economics of the battle for both sides. Big studios must plan for, and budget for, the cost of the updates, while Slysoft has to shoulder the time and effort required to break each new version. The need for such updates could also necessitate a review of the company's release schedule and software support.

At present, Slysoft is leading the charge against BD+; there are advantages to being incorporated in Antigua. A group of researchers from Doom9 is also working to develop a Linux-based, non-proprietary software package that can handle BD+. A recent Slashdot post that references efforts at Doom9 to break the scheme's RSA algorithm, however, is incorrect—according to the actual thread, the effort is meant to evaluate the strength of the RSA algorithm rather than cracking it.