From: kentborg@world.std.com (Kent Borg)
Date: Fri, 15 Jul 94 17:52:08 PDT
To: cypherpunks@toad.com
Subject: Re: Card Playing Protocol?
Message-ID: <199407160051.AA03924@world.std.com>
MIME-Version: 1.0
Content-Type: text/plain


jamiel@sybase.com wrote:
>What about implementing a Multiplayer Game Protocol?

Cool, but only to the extent it falls out nearly for free, being too
general is an enemy of actually getting results.  Besides, it seems a
better application of any urges to be general would be to work with
*any* transport medium from an alt.games.moves to IRC to email (AOL,
Compuserve, etc., in addition to Unix mail) to TCP/IP to pagers.  So
let's tag things and leave room for expansion with new tags, but let's
build one thing first.

Don't get me wrong, I would love for it to be general--like become the
basis for general purpose transactions--but the very fact that that
occurs to me warns me that it is best to make version 1.0 first, and
then 2.0, etc.  Plus, being general about allowing new tags will
certainly tweak the ITAR police.

Ben.Goren@asu.edu wrote:

>Just so people know: complete protocols for poker can be found in
>Schneier.  All you need is a snazzy GUI. 

Do you *really* think I would propose such a thing without a handy
place to crib from?  Some people!  Hell, I might have to write some
code here, and I'm lazy.

Oh, it would be nice to be bit more general than just poker.  Just a
deck of cards, places to put them, the ability to reshuffle and
rearrange stacks on the table, play cards from your hand, etc.  The
enforcement of plays is through the same technique as with a real
deck: other players are watching.  The cryptographic aspects are the
interesting ones, not implementing any particular game.  Besides, I'm
lazy, remember.

Ben.Goren@asu.edu also wrote:
>And, with ecash, you can even do all your betting.

Noooooo!  This is a political move.  It should be nothing more wicked
than a deck of cards.  (To some people that is bad enough.  Maybe
there would be a Rook option...)  

Just a deck of 52-cards (and how many for Rook?) and a table on which
to play.

And that worries me.  What are the fundamental operations with cards?

Can everything be modeled as different stacks on the table?  Some have
special privilages: I can see my hand, you can't; the top n-cards of
some stacks are visible to everyone; some stacks are visible to all
(playing a trick).  Any player can manipulate any card--though if you
grab one from my hand I might get upset, every player will see the
manipulation.  Some cards are face up (or once were), some are face
down (shuffled with the whole deck or a subset).  

Interesting realization: there is a set of card tricks which can be
performed in this environment and a set which cannot.  I suppose there
would then be a set of magicians who are willing to perform with this
deck and a set who will not.  (And how many will use magic tricks as
proof of having factored RSA-XXX?)

Where to put the information about face down cards: To make slow
interactions possible, is there a way every player can have all
information--but can be challanged that cards have not been peeked at?
And how to keep you from checking my hand in poker after
I--maybe--bluffed you into folding.  Hmm, there is a tension here.
Looks like I need to carefully read pages 78-81.


-kb, the Kent who is practicing looking innocent and saying things
like "Who me??  MUNITIONS???  All I wanted to do was to play gin
rummy.  With my mom in Minnesota."


--
Kent Borg                                                  +1 (617) 776-6899
kentborg@world.std.com                                
kentborg@aol.com                                      
          Proud to claim 32:00 hours of TV viewing so far in 1994!