Re: Getting random die rolls for a pbm game

From: matt@oddjob.uchicago.edu (Matt Crawford)

Date: Wed, 03 May 1989 00:33:14 +0000

What a coincidence.  Just last week I was considering the problem of
playing a fair game with dice by electronic mail without an independent
human moderator to roll the dice.

I've never played any games by mail which use dice, but I understand that
in postal games, a scheme like the following is used.  The player taking
his turn will insert a letter from the set {A, B, C, D, E, F} for each die
roll.  and mail his turn to his opponent.  On the same day, the opponent
sends a long sequence of letters from the set {U, V, W, X, Y, Z}.  An
agreed-upon table is used to turn each corresponding pair of letters (one
from A-F, one from U-Z) into a number from 1-6.

The problem with adapting this to electronic mail is that the travel time
for each message is often too short to guarantee that neither player has
seen the other's message before sending his own.  To solve this problem,
the players will have to trust some intermediate person or program.  A
design goal would be to require the least possible human intervention in
the trusted intermediary.

The best idea I had so far was to write a program with a database that
listed, for each game in progress:
	a name for the game
	the email addresses of the two players
	a password for each player
A trusted person would add games to the database, but even this step could
be automated.

The program would recieve moves (in the form of a message marked with the
game name) from a player, check that the player's password was enclosed,
then edit the message as follows:
	Delete the password.
	Find all die rolls, which would have some syntax like "{2d6+1}"
	meaning roll two six-sided dice and add one, and turn them into
	"{2d6+1=8}", where the number after the equal sign was generated
	at random.  Any delimiters ( "{" and "}" ) which did not enclose
	some text of the right syntax would have to be changed or flagged
	to prevent fraud.
Then the message would be sent separately to each player, with each
player's password enclosed on their own copy.

Refinements are possible, such as public-key cryptography instead of
simple passwords.

Oh dear.  The orginal question came from Finland and I used curly braces
in my example.  Scandinavians should probably pick some other delimiters.

So ... how much interest is there in an actual implementation?
________________________________________________________
Matt Crawford	     		matt@oddjob.uchicago.edu

References

Getting random die rolls for a pbm game
LK-HANNU@FINTUVM.BITNET (Hannu Pajunen)
Tue, 02 May 1989 14:00:28 +0000

Referenced By

Getting random die rolls for a pbm game
LK-HANNU@FINTUVM.BITNET (Hannu Pajunen)
Tue, 02 May 1989 14:00:28 +0000