brainwagon

Apparently, this memo has been out for a while, but I hadn’t seen it before. I know, I like to rant about Microsoft a lot, but it’s really quite interesting.

A Cost Analysis of Windows Vista Content Protection

Some quotes:

… so far no-one has been able to identify any Windows system that will actually play HD content in HD quality, in all cases any attempt to do this produced either no output or a message that it was blocked by content protection. While it’s not possible to prove a negative in this manner, it’s certainly an indication that potential buyers may be in for a shock when they try and play premium content on their shiny new Vista PC.

Protecting all of this precious premium content requires a lot of additional technology. Unfortunately much of this is owned by third parties and requires additional licensing. For example HDCP for HDMI is owned by Intel, so in order to send a signal over HDMI you have to pay royalties to Intel, even though you could do exactly the same thing for free over DVI (actually you could do it better, since DVI is provides a higher-quality link than HDMI). Similarly, since even AES-128 on a modern CPU isn’t fast enough to encrypt high-bandwidth content, companies are required to license the Intel- owned Cascaded Cipher, an AES-128-based transform that’s designed to offer a generally similar level of security but with less processing overhead.

In order to prevent tampering with in-system communications, all communication flows have to be encrypted and/or authenticated. For example content sent to video devices has to be encrypted with AES-128. This requirement for cryptography extends beyond basic content encryption to encompass not just data flowing over various buses but also command and control data flowing between software components.

In the interest of fairness,
here is Microsoft’s reponse. Some notable quotes:

Windows Vista includes content protection infrastructure specifically designed to help ensure that protected commercial audiovisual content, such as newly released HD-DVD or Blu-Ray discs, can be enjoyed on Windows Vista PCs.

This is simply nonsense of course. All available evidence is that the primary added “feature” that Windows Vista has is to degrade or prevent the playback of protected content. Microsoft has delivered a feature which no consumer demanded, and expects us, rather than the content providers to pay for it.

I’d go through more of the absurd marketing speak, but frankly, Gutmann does a much better job of it than I could. His rebuttal is contained at the bottom of his paper. Be sure to read it after Microsoft’s response.

[tags]Microsoft,Vista,No Thanks[/tags]

Addendum: Another terrific quote which accurately reflects the futility of DRM, even in the abstract:

In order for content to be displayed to users, it has to be copied numerous times. For example if you’re reading this document on the web then it’s been copied from the web server’s disk drive to server memory, copied to the server’s network buffers, copied across the Internet, copied to your PC’s network buffers, copied into main memory, copied to your browser’s disk cache, copied to the browser’s rendering engine, copied to the render/screen cache, and finally copied to your screen. If you’ve printed it out to read, several further rounds of copying have occurred. Windows Vista’s content protection (and DRM in general) assume that all of this copying can occur without any copying actually occurring, since the whole intent of DRM is to prevent copying. If you’re not versed in DRM doublethink this concept gets quite tricky to explain, but in terms of quantum mechanics the content enters a superposition of simultaneously copied and uncopied states until a user collapses its wave function by observing the content (in physics this is called quantum indeterminacy or the observer’s paradox). Depending on whether you follow the Copenhagen or many-worlds interpretation of quantum mechanics, things then either get weird or very weird. So in order for Windows Vista’s content protection to work, it has to be able to violate the laws of physics and create numerous copies that are simultaneously not copies.