Also known as
Windows Vista Content Protection.
A relevant quote from the article:
In fact, Microsoft is imposing a higher standard of security for premium content than what's been required in the past for any known secure computing initiative proposed for protecting data classified at
TOP SECRET or TS/SCI levels (the closest that anything came to what's required in Vista was the
LOCK kernel with SIDEARM and BED coprocessors (PDF link), which didn't go as far as the Vista requirements and after 17 years of development effort was a commercial failure to boot). Just to make this point clear, the level of security that Vista is trying to achieve to protect video and audio is more extreme than anything the US government has ever considered necessary for protecting its most sensitive classified data.