Macrovision, the DRM firm perhaps best known recently for creating security holes in Windows with its SafeDisc DRM, has purchased the intellectual property surrounding the BD+ DRM scheme used by Blu-ray to thwart attempts at copying. For $45 million, Macrovision will get ownership of the Self-Protecting Digital Content (SPDC) technology that forms the basis for BD+ as well as associated patents owned by Cryptography Research.

Both Blu-ray and HD DVD use AACS to thwart copying, but that was cracked last spring. Blu-ray is alone in using an additional layer of security, BD+, to keep users from copying Blu-ray discs. BD+ works via a small virtual machine that is launched each time a disc is inserted. The VM does some code transformation to correct deliberately-corrupted video streams, and checks to see if the disc is playing on a Blu-ray player known to have been hacked. If the player has been compromised in the past, playback can be disabled. When the disc is ejected, the VM disappears from memory, which, in theory, makes it more difficult to hack or reverse engineer.

One small problem: BD+ was hacked earlier this month by SlySoft, makers of AnyDVD. The crack made good the company's boast that a crack would be available by year end and called into serious question the claims made by Blu-ray's backers that BD+ was uncrackable.

With the crack, users of AnyDVD make copies of the movies for fair use purposes. Mandatory Managed Copy is part of the Blu-ray spec, but has yet to be implemented, meaning that there's no way for Blu-ray disc owners to legally copy the discs.

Despite the recent cracks, Macrovision is excited about owning BD+. "The integration of SPDC into our product portfolio will enable us to continue to provide innovative technology to our customers as they expand their distribution vehicles," said Macrovision CEO Fred Amoroso in a statement. "Not only is BD+ critical for content security, but it also supports value-added features that enhance the consumer playback experience, such as potentially unlocking bonus content."

Even if BD+ has been dented and its long-term viability is uncertain, it's still an important acquisition for Macrovision. The DRM company will now rake in the dough for BD+ licenses paid by the studios backing Blu-ray and will turn its expertise towards fighting hackers intent on defeating BD+.