AACS 2.1, which came with the 4K Ultra HD Blu-ray version of the movie 'Fury', appears to have been cracked only a month after the disc's release
Image/Photo Credit: Sony Pictures
The latest version of the copy protection scheme used by 4K Ultra HD Blu-ray discs has been cracked, according to the Russian company that makes the software DeUHD.
AACS (Advanced Access Content System) is the name of a digital rights management (DRM) scheme that has been in use on Blu-ray discs since the optical format's inception. An updated version of the scheme was put to use for the Ultra HD Blu-ray disc format, and has so far proved to be harder to crack than the original version.
The latest version of this copy protection scheme, version 2.1, was only put into "service" last month for the release of the tank battle movie 'Fury' on UHD Blu-ray. The previous iteration, version 2.0, had remained resilient until a crop of ripped UHD Blu-ray discs started to surface on the piracy scene, suggesting that a workaround, if not a full crack, has been found. A commercial ripping tool called DeUHD was then released by a Russian software company called Arusoft that took advantage of AACS 2.0's weakness to allow at-home ripping of UHD discs.
AACS 2.1 was an attempt to address version 2.0's weaknesses, but it too appears to have been cracked only a month after it surfaced. The makers of DeUHD officially announced that the latest version of the software will now support the ripping of 'Fury' and AACS 2.1, claiming that the software now rips more than 1100 UHD Blu-ray discs (as of June 11).
TorrentFreak reached out to Arusoft to ask them to explain how AACS 2.1 worked, and how a crack was devised. Arusoft was surprisingly forthcoming and explained that AACS 2.1 now used an encrypted m2ts file that now contains "forensic information".
"It is not too difficult to bypass this protection, just takes some time to do it," Arusoft told TorrentFreak.
The addition of "forensic information" suggests that studios are now trying ascertain the source of leaks via digital watermarking, which could make ripping and uploading 2.1 protected discs a risky proposition. However, Arusoft assures users that "redundant data has been cleared from the disc", suggesting, but not confirming, that forensic tracking data appears to have removed.