From: "Rick H. Wesson" <wessorh@ar.com>
Date: Tue, 23 Aug 94 21:21:30 PDT
To: cypherpunks@toad.com
Subject: Brands cash in perl
Message-ID: <199408240421.VAA09565@ar.com>
MIME-Version: 1.0
Content-Type: text/plain


Below are two Perl psudo-Functions as I see Brands Cash as described 
by Hal (hfinney@shell.portal.com) Am I comming close or am I way off,
Personally I understand code better than the written word and I can
loose lots in the translation. If this is on the "right track" then 
where does $g come from, can I take it from the modulo of a PGP 
key?


# mPrime(m') is passed as $CASH with the two submitter generated 
# Check values $A and $B. &GetChallenge returns the random challenge 
# we requested as $c0, the two additional ones ($c1 and $c2) were
# supplied by the depositor.

sub Deposit{
  local($CASH, $A, $B) = @_;
  if(($A*$B) == $CASH){
      ($c0, $c1, $c2) = &GetChalenge;
      $Catch = $A*($B ^ $c0);
      $Check = $Amt^$c1*$g^$c2;
      if($Catch == $Check){
         sql("insert into account Balacne=Balance+$CASH");
         print "ALL OK; CASH Accepted\n";
      }else{
         print "Double Spender!!\n"
         &CatchCriminal($CASH);
      }else{
         print "You Lie!!!\nStop making up stuff\n";
         &CatchCriminal($CASH);

   }
}

# Supplied with a users account number, however this happens via a form
# or E-Mail, we generate m' and sign and deliver it... 

sub mPrime{
   local($Acct, $Amt, $g) = @_;
   $RandomNumber = &GetHugeRandomNumber;

   $Acct = sql("Lookup $Person's Account");
   sql("update Balance=Balance-$Amt where AccountID=$Acct");

   $CASH = $Amt**$RandomNumber * $g**($Acct*$RandomNumber);
   
   sql("Intert $CASH into outstanding insterments");
   
   return(&Signed($CASH));
}