The widely discusses advanced access content system (AACS) that is supposed to prevent unauthorized duplications of Blu-ray and HD DVD discs has been reportedly cracked, meaning that users may now not only backup their high definition movies, but also make illegal copies of them.

“BackupHDDVD is a tool to decrypt a AACS protected movie that you own, so you can play it back later using an HDDVD player software,” a forum member of Doom9.org forums, which are dedicated to DVD, said. Users need to use the software, but provide it AACS crypto keys, which may not be easy to find.

Technology journalists from Engadget web-site have tried the utility and confirmed that it works. They were unable to playback files copied from the Full Metal Jacket HD DVD due to the lack of appropriate software, but this is only a matter of time when such programs emerge. It is remarkable that they used Microsoft Xbox 360 external HD DVD player plugged to a personal computer with special drivers to conduct the experiment.

Given that the advanced access content system technology is used on both Blu-ray and HD DVD, eventually both types of new high definition digital video disc formats will be fully “open” for backup and piracy, something, Hollywood studios hoped would never happen. In addition to AACS, both formats utilize high-bandwidth digital copyright protection (HDCP) technology, which does not allow to intercept digital video signals to make illegal copies or playback movies in full HD (1920x1080 progressive, 1080p) resolution when analogue cables are used. The latter feature called image constraint token (ICT) is not implemented currently.

Traditional single-layer DVDs allow consumers to watch movies in 720x480 (NTSC) or 720x576 (PAL) resolution with Dolby Digital audio. The blue-laser discs, such as Blu-ray and HD DVD, provide consumers 1920x1080 progressive (1080p) resolution as well as DTS or Dolby Digital Plus audio along with some additional interactive features.