From: baum@apple.com (Allen J. Baum)
Date: Wed, 31 Jan 1996 11:51:54 +0800
To: cypherpunks@toad.com
Subject: Re: Random number generator question (& Las Vegas)
Message-ID: <v02130506ad3332c4d9eb@[17.255.11.191]>
MIME-Version: 1.0
Content-Type: text/plain


>>fair@clock.org ("Erik E. Fair"  (Time Keeper)) writes:
>>>does anyone know what sorts of random number generators those
>>>electronic games use, and how (if at all) they are measured and regulated
>>>by the Nevada Gaming Commission? They might have something to teach us.

>>Several people who work in the industry said that electronic machines
>>use some sort of PRNG, but with a nice added bit of random input - the
>>player's timing of hitting the buttons. One poster described it as the
>>machine constantly generating numbers, and choosing the payoff based
>>on the last number generated when the user hit a button.

According to a friend who started a company that is going to sell gambling
machines to Las Vegas:

The Nevada Gaming Commission closley regulates the RNGs.  They use Chi
squared tests and others to verify the randomness.  They are not perfect.

Todays slot machines use a Psudo RNG that requires a seed number to make
sure it doesn't short cycle.  They use some time based player input like
coin in or handle pulls to pick a number.  You must discard lots of numbers
or it would be too easy to sync up and predict the answer. (basically
confirming the above)

Nothing is totally immune to tampering.  The gaming commission tries to
make sure the machines are reasonable secure.

**************************************************
* Allen J. Baum              tel. (408)974-3385  *
* Apple Computer, MS/305-3B  fax  (408)974-0907  *
* 1 Infinite Loop                                *
* Cupertino, CA 95014        baum@apple.com      *
**************************************************