From: "Alex F" <alexf@iss.net>
Date: Wed, 24 Jul 1996 20:36:55 +0800
To: tcmay@got.net (Timothy C. May)
Subject: Re: Digital Watermarks for copy protection in recent Billbo
Message-ID: <199607231840.OAA07655@phoenix.iss.net>
MIME-Version: 1.0
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> >  People buying CDs at a garage sale & getting arrested for
> >piracy.  Wonderful.
> 
> Arrests like this are uncommon. Even buying "cheap bikes" and other "cheap"
> (= probably stolen and fenced) merchandise almost never subjects the
> purchaser to criminal sanctions.

Yes, but concievably if (whoever would be incharge, FBI?) *could*, 
under law do this, even if they are wrong.  It is a lot harder to 
prove that they intentionally harrassed *you* than it is for them to 
say that they were following leads and show evidence.  Yes, this may 
never happen, but the mere fact that it *could* is uncomforting.  
Kinda like the CDA an Clinton saying "we will not enforce this...."  
Fine, but there is still a law on the books that allows them to if 
they decide to change their mind.  Even if you can't be found guilty, 
you could still be ruined by legal fees, job loss, etc.

> ("Alice's Restaurant" not to the contrary; the confession to Officer Obie
> cinched his fate.)

Don't wanna end up on that "Group-W" bench!  :)

> >  It would be trivial to add a digital ID signal at,
> >say 30,000 or 15 or something like that.  This could then be decoded,
> 
> Doubtful. The existing CD standard tops out at a Nyquist limit of about
> 20KHz, with the actual sampling at 44 KHz--but there is simply "nothing" at
> above 20-22KHz. Putting a signal in at "30 KHz" is simply not possible,
> given the Nyquist Theorem and the CD sampling rate.

Cds are often sampled at 48 these days.  Mine was, and we had to 
reduce it to 44.1 for mass producing (much to our surprise, since 
many CD manufacturers love getting stuff at 48 over 44.1)

Not familiar with the Nyquist limit w/ regards to sampling rate vs 
frequency :(

Alex F
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Alex F    alexf@iss.net
Marketing Specialist
Internet Security Systems
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