Trusted Computing Platforms

If you were applying a little creative thinking during the preceding discussion of the DRM reference architecture, you probably thought of several ways that the scheme could be defeated. That issue is the chief weakness of DRM. As we've seen, for the user to view or otherwise use the content, it has to be rendered in a usable format, and that allows ample opportunity for the content to be redirected to a use that wasn't specifically authorized.

The iTunes example illustrates some of the problems :

These examples show just how hard it is to really protect content in a digital format. In addition to the tradeoffs made by Apple that were examined in the case study, Apple is inconveniencing their legitimate users while still allowing the rights of copyright holders to be undermined by determined crackers.

These problems have led to numerous calls for trusted computing platforms that would ensure that the DRM client was run in an environment that kept even determined attackers from gaining access to protected content illegitimately. The basic idea is to protect every component of the end-user system in a way that disallows illegitimate use. When we say "every component," we're being literal—right down to the keyboard. Building a trusted computing platform requires the cooperation and coordination of both hardware and software manufacturers in very sophisticated way.

The nature of trusted computing systems and the debate surrounding them is beyond the scope of this book, but they are being advanced by companies as powerful as Microsoft and Intel and countered by numerous user advocacy groups. Because trusted computing platforms are still in the future, DRM will remain an exercise in making the theft of unauthorized rights sufficiently inconvenient that most users will only access content legitimately.