December 23, 2024

Blu-Ray Tries to Out-DRM HD-DVD

Blu-Ray, one of the two competing next-gen DVD standards, has decided to up the ante by adopting even more fruitless anti-copying mechanism than the rival HD-DVD system. Blu-Ray will join HD-DVD in using the AACS technology (with its competition-limiting digital imprimatur). Blu-Ray will add two more technologies, called ROM-Mark and BD+.

ROM-Mark claims to put a hidden mark on all licensed discs. The mark will be detected by Blu-Ray players, which will refuse to play discs that don’t have it. But, somehow, it is supposed to be impossible for unlicensed disc makers to put marks on their discs. It’s not at all clear how this is supposed to work, but systems of this sort have always failed in the past, because it has always proved possible to make an exact copy of a licensed disc (including the mark).

BD+ will apparently allow the central Blu-Ray entity to update the anti-copying software in Blu-Ray players. This kind of updatability will inevitably add to the cost, complexity, and fragility of Blu-Ray players. Trying to do this raises some nasty technical issues that may not be solvable. I would like to find out more about how they think they can make this happen, especially for (say) cheap, portable players. (This technology was reportedly Fox’s reason for joining the Blu-Ray camp.)

As always, content will be copied regardless of what they try to do, and the main effect of these technologies will be to make player devices more expensive and less reliable, and to limit entry to the market for the devices. My guess is that some movie studio people actually believe these technologies will stop copying; and some know the technology won’t stop copying but want the power to limit entry.

Both groups must be happy to see the Blu-Ray and HD-DVD camps competing to make the most extravagant copy-prevention promises. To law-abiding consumers, each step in this bidding war means more expensive, less capable technologies.

Hollywood Controlling Parts of Windows Vista Design

A recent white paper (2MB Word file) from Microsoft details the planned “output content protection” in the upcoming Windows Vista (previously known as Longhorn) operating system product. It’s a remarkable document, illustrating the real costs of Hollywood’s quest to redesign the PC’s video hardware and software.

The document reveals that movie studios will have explicit veto power over what is included in some parts of Vista. For example, pages 22-24 describe the “High Bandwidth Cipher” which will be used to encrypt video data is it passes across the PC’s internal PCIe bus. Hollywood will allow the use of the AES cipher, but many PCs won’t be able to run AES fast enough, leading to stutter in the video. People are free to design their own ciphers, but they must go through an approval process before being included in Windows Vista. The second criterion for acceptance is this:

Content industry acceptance
The evidence must be presented to Hollywood and other content owners, and they must agree that it provides the required level of security. Written proof from at least three of the major Hollywood studios is required.

The document also describes how rational designs are made more expensive and complicated, or ruled out entirely, by the “robustness” rules Hollywood is demanding. Here’s an example, from page 27:

Given the data throughput possible with PCIe, there is a new class of discrete graphics cards that, to reduce costs, do not have much memory on the board. They use system memory accessed over the PCIe bus.

In the limit, this lack of local memory means that, for example, to decode, de-interlace, and render a frame of HD may require that an HD frame be sent backward and forward over the PCIe bus many times – it could be as many as 10 times.

The frames of premium content are required to be [encrypted] as they pass over the PCIe bus to system memory, and decrypted when they safely return to the graphics chip. It is the responsibility of the graphics chip to perform the encryption and decryption.

Depending on the hardware implementation, the on-chip cipher engine [which wouldn’t be necessary absent the “robustness” requirements] might, or might not, go fast enough to encrypt the 3 GByte/sec (in each direction) memory data bandwidth.

These are just a few examples from a document that describes one compromise after another, in which performance, cost, and flexibility are sacrificed in a futile effort to prevent video content from leaking to the darknet. And the cost is high. As just one example, nearly all of us will have to discard our PC’s monitors and buy new ones to take advantage of new features that Microsoft could provide – more easily and at lower cost – on our existing monitors, if Hollywood would only allow it.

There can be little doubt that Microsoft is doing this because Hollywood demands it; and there won’t be much doubt among independent security experts that none of these compromises will make a dent in the availability of infringing video online. Law-abiding people will be paying more for PCs, and doing less with them, because of the Hollywood-decreed micromanagement of graphics system design.

DRM Textbooks Offered to Princeton Students

There’s a story going around the blogosphere that Princeton is experimenting with DRMed e-textbooks. Here’s an example:

Princeton University, intellectual home of Edward Felten and Alex Halderman, has evidently begun to experiment with DRM’d textbooks. According to this post, there are quite a few digital restrictions being managed:

  • Textbook is locked to the computer where you downloaded it from;
  • Copying and burning to CD is prohibited;
  • Printing is limited to small passages;
  • Unless otherwise stated, textbook activation expires after 5 months (*gasp*);
  • Activated textbooks are not returnable;
  • Buyback is not possible.

There an official press release from the publishers for download here.

Several people have written, asking for my opinion on this.

First, a correction. As far as I can tell, Princeton University has no part in this experiment. The Princeton University Store, a bookstore that is located on the edge of the campus but is not affiliated with the University, will be the entity offering DRMed textbooks. The DRM company’s press release tries to leave the impression that Princeton University itself is involved, but this appears to be incorrect.

In any case, I don’t see a reason to object to the U-Store offering these e-books, as long as students are informed about the DRM limitations and can still get the dead-tree version instead. It’s hard to see the value proposition for students in the DRMed version, unless the price is very low. It appears the price will be about two-thirds of the new-book price, which is obviously a bad deal. Our students are smart enough to know which version to buy – and the faculty will be happy to advise them if they’re not sure.

I don’t object to other people wasting their money developing products that consumers won’t want. People waste their money on foolish schemes every day. I wish for their sake that they would be smarter. But why should I object to this product or try to stop it? A product this weak will die on its own.

The problem with DRM is not that bad products can be offered, but that public policy sometimes protects bad products by thwarting the free market and the free flow of ideas. The market will kill DRM, if the market is allowed to operate.

UPDATE (August 12): The DRM vendor announced yesterday that usage restrictions will be eased somewhat. The expiration time has been extended to at least twelve months (longer for some publishers), and restrictions on printing have been loosened in some cases.

Harry Potter and the Half-Baked Plan

Despite J.K. Rowling’s decision not to offer the new Harry Potter book in e-book format, it took less than a day for fans to scan the book and assemble an unauthorized electronic version, which is reportedly circulating on the Internet.

If Rowling thought that her decision against e-book release would prevent infringement, then she needs to learn more about Muggle technology. (It’s not certain that her e-book decision was driven by infringement worries. Kids’ books apparently sell much worse as e-books than comparable adult books do, so she might have thought there would be insufficient demand for the e-book. But really – insufficient demand for Harry Potter this week? Not likely.)

It’s a common mistake to think that digital distribution leads to infringement, so that one can prevent infringement by sticking with analog distribution. Hollywood made this argument in the broadcast flag proceeding, saying that the switch to digital broadcasting of television would make the infringement problem so much worse – and the FCC even bought it.

As Harry Potter teaches us, what enables online infringement is not digital release of the work, but digital redistribution by users. And a work can be redistributed digitally, regardless of whether it was originally released in digital or analog form. Analog books can be scanned digitally; analog audio can be recorded digitally; analog video can be camcorded digitally. The resulting digital copies can be redistributed.

(This phenomenon is sometimes called the “analog hole”, but that term is misleading because the copyability of analog information is not an exception to the normal rule but a continuation of it. Objects made of copper are subject to gravity, but we don’t call that fact the “copper hole”. We just call it gravity, and we know that all objects are subject to it. Similarly, analog information is subject to digital copying because all information is subject to digital copying.)

If anything, releasing a work a work in digital form will reduce online infringement, by giving people who want a digital copy a way to pay for it. Having analog and digital versions that offer different value propositions to customers also enables tricky pricing strategies that can capture more revenue. Copyright owners can lead the digital parade or sit on the sidelines and watch it go by; but one way or another, there is going to be a parade.

HD-DVD Requires Digital Imprimatur

Last week I wrote about the antitrust issues raised by the use of encryption to “protect” content. Here’s a concrete example.

HD-DVD, one of the two candidates for the next-gen DVD format, uses a “content protection” technology called AACS. And AACS, it turns out, requires a digital imprimatur on any content before it can be published.

(The imprimatur – the term is Latin for “let it be printed” – was an early technology of censorship. The original imprimatur was a stamp of approval granted by a Catholic bishop to certify that a work was free from doctrinal or moral error. In some times and places, it was illegal to print a work that didn’t have an imprimatur. Today, the term refers to any system in which a central entity must approve works before they can be published.)

The technical details are in the AACS Pre-recorded Video Book Specification. The digital imprimatur is called a “content certificate” (see p. 5 for overview), and is created “at a secure facility operated by [the AACS organization]” (p. 8 ). It is forbidden to publish any work without an imprimatur, and player devices are forbidden to play any work that lacks an imprimatur.

Like the original imprimatur, the AACS one can be revoked retroactively. AACS calls this “content revocation”. Every disc that is manufactured is required to carry an up-to-date list of revoked works. Player devices are required to keep track of which works have been revoked, and to refuse to play revoked works.

The AACS documents avoid giving a rationale for this feature. The closest they come to a rationale is a statement that the system was designed so that “[c]ompliant players can authenticate that content came from an authorized, licensed replicator” (p. 1). But the system as described does not seem designed for that goal – if it were, the disc would be signed (and the signature possibly revoked) by the replicator, not by the central AACS organization. Also, the actual design replaces “can authenticate” by “must authenticate, and must refuse to play if authentication fails”.

The goal of HD-DVD is to become the dominant format for release of movies. If this happens, the HD-DVD/AACS imprimatur will be ripe for anticompetitive abuses. Who will decide when the imprimatur will be used, and how? Apparently it will be the AACS organization. We don’t know how that organization is run, but we know that its founding members are Disney, IBM, Intel, Microsoft, Panasonic, Sony, Toshiba, and Warner Brothers. A briefing on the AACS site explains the “AACS Structure” by listing the founders.

I hope the antitrust authorities are watching this very closely. I hope, too, that consumers are watching and will vote with their dollars against this kind of system.