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1 Advanced Access Content System – Hollywood against Microsoft – how it all started

August 22nd, 2007 · No Comments ·

Related stories:

Is digital rights management (DRM) dead? EMI must think so

So what is all the fuss about – Peter Gutmann, Jon Brodkin, Ken Fisher, George Ou, Ed Bott
A while back we reported about Peter Gutmann, who issued his criticisms several months ago with a paper titled:
A Cost Analysis of Windows Vista Content Protection
Now some people are beginning to ask about these claims Peter Gutmann put forward for which he has so far not provided any data that would confirm or disconfirm some of his claims — a basic requirement that distinguishes journalism from scientific work.

For some of you AACS may stand for American Academy of Cosmetic Surgery (AACS) but in the IT world, this term stands for:Advanced Access Content System (AACS) – founding members are IBM, Intel, Microsoft, Panasonic, Sony, Toshiba, The Walt Disney Company, Warner Bros. Studio


AACS is the copy protection scheme for next-generation video disks regardless of who wins the blu-ray vs. HD-DVD wars, and regardless of whose coder-decoder are used. In this context, a coder-decoder is a digital algorithm, typically executed in software, which transforms a media signal into a form optimized for transmission or storage, and then transforms it back again.

Early in 2007, a crack emerged, at least for HD-DVD, a software implementation of the AACS cryptography specification. While it fails to work without secret per-title keys, unfortunately, compromised software players have yielded many such keys. In turn, the latter have been posted on the Internet. Considering the small selection of ND-DVD titles available, this represents a substantial fraction of the HD-DVD movie inventory. Further, many of the HD-DVD security mechanisms, such as Traitor Tracing and revocation, are not useful agsinst this attack, because:

a) keys produced from compromised machines are not traceable and

b) the users of the keys would not need to do anything which could be detected as a revocation trigger.

We reported about the above based on our own tests here:

CyTRAP Labs advisory – AACS DRM cracked by BackupHDDVD tool – our tests show it works nicely

AACS DRM is an attempt by content providers, such as the movie studios and Microsoft to protect content. However, as the music industry has discovered with DVD it might not work.

However, even if it might fail to do the trick for video and movie entertainment distribution, in the meantime it allows Microsoft to get a better handle on the distribution channel to many PC users out there. Apple has demonstrated that this kind of control can do wonders for revenues and your share price with the iPod and iTunes.

The half truths about Digital Rights Management (DRM) and your iPod


Peter Gutmann put forward some provocative claims regarding Windows Vista content protection in a paper he published in December 2006. We provided a synopsis of the claim made in the paper here including a link to the original:

2007-01-16 – Windows Vista content protection will cost users dearly

The biggest challenge is that Gutmann did not provide much data regarding his claims since he first released the above paper a while back

As any academic with a tenured full-time job would do, Gutmann made some statements and put forward some propositions but refrained from presenting some testable

– research questions, or

– hypotheses

Such kind of inductive reasoning is sometimes done when researchers may be unable to base their reasoning on past research that could suggest further avenues of inquiry. But already pretty early, people started to ask questions about the merit of some of these claims, such as:

2007-01-16 – CyTRAP Labs (2007-01-16) Does Gutman have a case at all? (see towards end of this entry)

Bruce Schneier (2007-02-12) Security Matters – Why Vista’s DRM Is Bad For You — published in Forbes

We will follow-up on this next week regarding debunking some claims made by Gutmann.


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