limits of watermarking (Re: First Steganographic Image in the Wild)

[Adam Back]

Ben Laurie wrote:
> The other obvious weakness in such a scheme is that the player can
> be modified to ignore the result of the check - rather like
> defeating dongles, which have yet to exhibit any noticable
> resistance to crackers.

I think though that that weakness is more workablee -- for example
playstations can be "chipped" to work from copies of CDs, however
probably the proportion of the market willing to make hardware
modifications is sufficiently low that the copying rate is not a
significant financial loss to the distributor (especially after
adjusting for people who wouldn't have bought the work anyway, which
is the group most likely to make the modification (students with low
budgets etc)).

Things which can be defeated in software or firmware upgrades only are
for more fragile, and subject to changing user demographics, more
internet aware and connected users, increasing scale of file-sharing
networks; whereas devices needing hardware modifications have non-zero
reproduction costs, and risk of damaging expensive equipment in the
operation.

On Wed, Oct 17, 2001 at 10:23:03AM +0100, Ben Laurie wrote:
> Adam Back wrote:
> > [...why copymarks don't work...]
>
> [...]
> It seems to me that putting the details of the purchaser in plaintext on
> the beginning of the file and making it illegal to remove it is as good
> a protection as you are ever going to get - but that would ruin a whole
> bunch of business plans, so I guess no "expert" is going to admit that.

It may be more to do with attempts to qualify under legal provisions
of DMCA to construct something which is (legally) arguable qualifying
as a system intended to prevent copying, so they can sue people who
by-pass it.

Another argument I've heard for making dumb proprietary schemes is
that they ened them to be proprietary so they can make onerous
conditions part of the licensing agreement, and sue anyone who makes
devices or software without licensing their broken technology from
them.  In effect that it's utterly broken doesn't matter -- that it's
claimable as an "original" work under patent law matters.

> In short, the agenda, it seems to me, is the business plans of
> companies in the watermarking business.

That too is doubtless part of the problem.  IBM's cryptolopes lending
credibility by brand recognition to related technologically broken
efforts such as InterTrust and other watermark related business plan
startups "digi-boxes" and the like.  SDMI was another broken attempt.

> No more, no less. I'm amazed the media moguls are willing to waste
> so much of their time and money on it.

It could be that the only thing keeping the InterTrust types in
business is the patentability and DMCA qualifying legal arguments
above.  Technologically they are all systemically broken.

There may be an element of technological naivete on the part of MPAA
RIAA too though, perhaps decision makers were genuinely confused to
start with, and crypto-box outfits will have incentives to exaggerage
the technological properties of their systems to their customers, the
RIAA, DMCA etc.

Adam



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