From: "Deranged Mutant" <WlkngOwl@unix.asb.com>
Date: Sat, 13 Jul 1996 01:17:44 +0800
To: cypherpunks@toad.com
Subject: Digital Watermarks for copy protection in recent Billboard magaz
Message-ID: <199607121211.IAA25703@unix.asb.com>
MIME-Version: 1.0
Content-Type: text/plain


Paged through a recent (June or July 13) edition of Billboard 
magazine yesterday.  There was an article about the music industry, 
the internet, and copyright issues.  Didn't have a chance to read in 
thoroughly, but it mentioned using digital watermarks which contained 
info on to who (CC number) and when the material was sold... the
watermarks allgedly could survive if a CD was taped, copied several times
and redigitized.

It's rather interesting for several reasons... imagine if every CD 
you owned was tagged with a link to your identity.  So imagine 
getting a used CD or from a garage sale... after several years a 
pirated edition is floating around the internet...

The anti-piracy scheme is only useful for direct sale to a customer 
though.  If you buy music anonymously, how is it traced?  This only 
works for pirating on-demand purchases.

Other issues: what if an eavesdropper steals the music or video? It's 
tagged with your ID.  If he spreads pirated material, you get in 
trouble even though it's not nec. your fault (if no secure 
communications are available, anyway).

If it uses a credit-card number as (part of) an ID, that's pretty 
bad.  Someone can sniff for CC numbers if they know how it's stored.

The system will have to rely on proprietary tech and security through 
obscurity.  Even know how watermarks are stored without understanding 
the math, one must be able to somehow garble the sound without 
distorting it, but which renders the watermark useless.

That a watermark can survive when the music is converted to analog 
and then redigitized is interesting... (if it's saved as inaudible 
tones, what's to prevent one from blurting them out with noise in 
those frequencies?)

Guess I'll have to hunt down that issue and post useful excerpts from 
it...in terms of far use, of course. (Or perhaps an alt-vista 
search...)


Rob
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