Originally Posted by llasram
- A fully-specified open DRM scheme. The impossibility is that "open DRM" is an oxymoron. Either parts of the system are still closed and vendor-specific, or anyone is free to use the specification to implement a DRM-removal tool.
DRM is the problem in itself, not the specification of DRM in EPUB.
Actually, now that I think about it, why is that impossible? An open DRM scheme is easier to crack, but closing the DRM doesn't really guarantee it wont be cracked. The only real defence DRM has against being cracked is a legal one. For example, MOBI DRM is trivial to crack if you have the PIN used to encrypt the file, and not so trivial if you don't. In fact, MOBI DRM is a de-facto open DRM scheme.