From: "John Kelsey" <kelsey@plnet.net>
Date: Mon, 3 Nov 1997 02:11:21 +0800
To: "Perry's Crypto List" <cypherpunks@Algebra.COM>
Subject: Copyright commerce and the street musician protocol
Message-ID: <199711021807.MAA30019@email.plnet.net>
MIME-Version: 1.0
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[ To: Perry's Crypto List, Cypherpunks ## Date: 11/01/97 ##
  Subject: Copyright commerce and the street musician protocol ]

I've been working on various copyright protection schemes
from time to time over the last three years.  The general
goal is (naturally enough) to make some digital data hard to
copy without some kind of permission or payment or record
being made.  Thus, a user may have a book (mostly text,
perhaps with some illustrations) he is reading on his
computer, and the publisher wants to make sure that that
user can't give copies of the book to all his friends, or
post it to the net, or whatever.

I'm convinced that there will never be a secure solution to
this problem.  (I can't imagine that this is news to anyone
on these two lists.)  I have somewhat mixed feelings about
this--I'd hate to see my favorite authors and musicians
either waiting tables for a living, or having to insert
references to their sponsors' products in their stories.
(``And then he bought her a Coke, and her eyes lit up.'') On
the other hand, a widespread copyright commerce system that
really works is most of the infrastructure for a massive
censorship mechanism.  (Reset the price of books you don't
like to a billion dollars US per copy made.)

Suppose I want to get paid for the next chapter of my
thrilling novel.  A whole bunch of people want to see me
publish my next chapter.  So, I make some statement like
``When I get $1,000 in donations, I will publish
the next chapter in this novel.''  Readers can go to my
website, see how much further there is to go, and donate
money to the cause of getting my novel out.  Note that I,
the author, don't care *who* pays to get the next chapter
out; nor do I care about free riders.  Instead, I just care
that my $1,000 pot gets filled.  When it does, I publish the
next chapter.

There are basically three things that can go wrong here:

a.  I set my price too high, and never reach my amount.  (It
might be possible to decrease the total amount required
later, though it would be a little questionable to do this
often.)

b.  I set my price too low, and get lots less than I could
have gotten.  (This is self-correcting.)

c.  I get my amount filled, but still don't publish the next
chapter of my novel.

The trust issues, especially with (c), are worth
considering.  The obvious (clunky) way to solve this is to
have a trusted third party handle the whole transaction.  We
will call him the Publisher.

Now, I submit my novel, or parts of it, to the Publisher.
He has his editors review it to see if it's worth trying to
sell (like any publisher, albeit with rather low
printing/binding costs).  If so, he and I agree on a price
and split.  For unknown authors, the first several chapters,
or even the first few books, may be freely available, in
hopes of drawing in customers.  For known authors, perhaps
the first chapter or two is free, and the rest go through
the payment mechanism.  He has my whole novel, and on his
web site, he makes available, say, chapters 1-3 for free,
and chapter 4 will become available when $1000 is donated to
the cause of getting it out, or on January 1, 1998.

If enough readers want to hurry up and see the next chapter,
they can make a payment.  The publisher needs no
identification for this, so anonymous payment systems work
quite well.  The Publisher holds the payments in escrow
until the chapter is released, and then sends me my cut.

I think I can build a similar protocol without the Publisher
taking anything but a backup role--he gets the money
transfers and holds them in escrow, and if the chpater isn't
released, either he can release it or he can return the
money, or donate it to some charity, or whatever.  (The
whatever has to be spelled out beforehand, and the money
mustn't go to the author, directly or indirectly.)

This is obviously not a complete solution.  The neat thing
is, it can be used with other systems.  (Thus, if you want
to include a shareware/guiltware message on each copy, or
try to use some kind of software or hardware protection for
the chapters once they're published, then this system
doesn't alter that much--the donors simply get prepurchased
copies of the book, released on the normal release date.)

Similar ideas may work in other areas.  In software, I
suspect it would be a way of getting a feel from the market
for what new features are wanted.  In music, perhaps this
could be used for individual songs, or maybe it would work
better for whole albums.  Television and movie serials could
work this way (it works for PBS, doesn't it?).  Some books,
music, and movies would be *awful* to release this way,
though.  I wish I had a more useful general solution, but
maybe this will help a little.

Comments?  This is clearly not all that new, but I've never
seen it in a crypto context from anyone but me.

   --John Kelsey, Counterpane Systems, kelsey@counterpane.com
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   --John Kelsey, Counterpane Systems, kelsey@counterpane.com
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