Re: Getting random die rolls for a pbm game

From: Martin-Charles@cs.yale.edu (Charles Martin)

Date: Wed, 03 May 1989 13:54:29 +0000

Each player resolves the opponent's attacks (attacks are specified in
one email note, the reply has the results).  When you send your
attacks, you also send two numbers, one of which is encrypted, and a
key.  The encrypted number is the seed you will use for the random
number generator the next time that you resolve the opponent's move.
The key is the key for the encryption you used the previous time (for
verification).  The unencrypted number is added to the opponent's seed
to create the true seed for resolving your attacks.

Assuming Afrika Korps, here is what the messages look like:

Allies: Encrypted number X1

Axis:   Move and attacks
    	    Encrypted number X2
    	    Number N2

Allies: Resolution of Axis move with seed X1+N2
    	    Encryption key K1 for X1
    	    Move and attacks
    	    Encrypted number X3
    	    Number N3

Axis:   Resolution of Allied move with seed X2+N3
    	    Encryption key K2 for X2
    	    Move and attacks
    	    Encrypted number X4
    	    Number N4

...etc.  This would be made a lot easier if someone would write a
little C program using 'crypt', etc., that had the following i/o:

% pbemail
    Do turn result, encrypt a number, or quit? [req] r
    Encrypted number? 123
    Encryption key? abc
    Number? 456
    Move file? axis1.txt
    Writing move results in file axis1.txt.r
    Do turn result, encrypt a number, or quit? [req] e
    Number? 789
    Encryption key? def
    Encrypted number is 147
    Do turn result, encrypt a number, or quit? [req] q
    %

The idea would be that you would save your opponent's move message in
a file such as 'axis1.txt'.  Every dice roll needed would be specified
in the message in the form 2d6+3.  The program would write a new file
with extension '.r' which replaced every occurance of 'xdy+z' with
'xdy+z=r', where 'r' is the result.  Then you would just send that
file back.  Obviously, you can use this to verify your own results.

Okay, who wants to write that program?  I think this is a lot simpler
than Matt's server program...

Charles

References

Getting random die rolls for a pbm game
LK-HANNU@FINTUVM.BITNET (Hannu Pajunen)
Tue, 02 May 1989 14:00:28 +0000
Re: Getting random die rolls for a pbm game
matt@oddjob.uchicago.edu (Matt Crawford)
Wed, 03 May 1989 00:33:14 +0000