AACS

The proposal was voted one of the technologies most likely to fail by IEEE Spectrum magazine's readers in the January 2005 issue [1]. Concerns about the approach include its similarity to past systems that failed, such as Content Scrambling System (CSS), and the inability to preserve security against attacks that compromise large numbers of players. Jon Lech Johansen ("DVD Jon"), who defeated the original DVD CSS, expected AACS to be cracked by winter 2006/2007 [2].

In late 2006, security expert Peter Gutmann released A Cost Analysis of Windows Vista Content Protection, a technical paper criticizing the implementation of AACS on Windows Vista.

Providing this protection incurs considerable costs in terms of system performance, system stability, technical support overhead, and hardware and software cost. These issues affect not only users of Vista but the entire PC industry, since the effects of the protection measures extend to cover all hardware and software that will ever come into contact with Vista, even if it's not used directly with Vista (for example hardware in a Macintosh computer or on a Linux server).

在2006年7月，the first steps towards enabling full AACS-encrypted films to be copied were taken. While great care has been taken with AACS to ensure that contents are encrypted right up to the display device, it was discovered that a perfect copy of any still frame from a film could be captured from certain Blu-ray and HD DVD software players made simply by utilizing the Print Screen function of the Windows operating system. It was hypothesized that this approach could be automated to allow a perfect copy of an entire film to be made, in much the same way that DVD films were copied before the advent of DeCSS, but to date no such copy has been discovered, and this exploit has been closed in subsequent software versions.

Such approaches do not constitute compromises of the AACS encryption itself, relying instead on an officially licensed software player to perform the decryption. As such, the output data will not be in the form of the compressed video from the disc, but rather decompressed video.

2007年1月26日，BBC reported "The AACS group has admitted that a hacker [muslix64] had managed to decrypt some discs and other people were now able to make copies of certain titles." In a recent interview muslix64 said the reason he hacked the AACS was he got angry when a HD-DVD he bought wouldn't play on his monitor because it didn't have the compliant connector. He says "Not being able to play a movie that I have paid for, because some executive in Hollywood decided I cannot, made me mad." Muslix64 also said "I'm just an upset customer. My efforts can be called 'fair use enforcement'."