Applaud Warners

[Julian T J Midgley]

On Wed, 3 Jul 2002, Ben Laurie wrote:
>
> > The article doesn't mention CSS (content
> > scrambling system), which incidentally is a DRM system rather than copy
> > protection.
>
> Err - the difference being?

Digital Rights Management is a broad, catchall term for a system that
somehow enforces a set of rights associated with a particular user or
users and a particular object (piece of text, music, or whatever).  If
were to create a wrapper for PDF that permitted you to copy the file as
much as you like, but only print it if you'd paid for an authorization
key, that would be DRM, but there wouldn't be copy-protection (or at
least, not with respect to copies made on disk).

Perhaps a better example would be a file that could only be edited with
appropriate authorisation, but could be copied and printed by all.

Similarly, watermarking schemes can form part of a DRM system (enabling
the source of illegal copies to be traced) without actually preventing
copying in any way.

Julian


-- 
Julian T. J. Midgley                      http://www.xenoclast.org/
Cambridge, England.                          PGP Key ID: 0xBCC7863F