privacy <> digital rights management

[John S. Denker]

Dan Geer wrote:
> 
> Over the last six months, I'd discovered that Carl Ellison (Intel),
> Joan Feigenbaum (Yale) and I agreed on at least one thing: that the
> problem statements for "privacy" and for "digital rights management"
> were identical, 
...
> ... YMMV.

Uhhh, my mileage varies rather considerably.  Perhaps we are using
wildly divergent notions of "privacy" -- or wildly divergent
notions of "identical".

DRM has to do mainly with protecting certain rights to _published_
material.  Private material is not "identical" with published
material -- it is more opposite than identical.

Private material is, according to the usual definitions, in the hands 
of persons who have a common interest in keeping the information
private and restricted.  Published material, in contrast, is in the 
hands of persons who have no interest in keeping it private, and 
indeed commonly have an interest in defeating whatever restrictions
are in place.

We have thousands of years of experience with military crypto, where 
the parties at both ends of the conversation are highly motivated to
restrict the flow of private information.  The current state of this
technology is very robust.

Ending about 20 years ago we had a 500-year era where it was not
practical for anyone except an established publisher to infringe
copyrights in a big way.  During this era, Rights Management had
essentially nothing to do with crypto;  it mainly had to do with 
the economics of printing presses and radio transmitters, supplemented 
by copyright laws that were more-or-less enforceable.  This era 
was killed by analog means (widespread photocopy machines) and 
the corpse was pulverized by digital means (widespread computers
and networking).

I repeat:  The main features of our experience with Privacy Management
are disjoint from the main features of our experience with Publishers'
Rights Management.  They are about as different as different can be.
The record is replete with spectacular failures attributable to 
non-understanding of the difference.

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