From: Vincent Cate <vince@offshore.com.ai>
Date: Thu, 21 Sep 95 15:22:52 PDT
To: cypherpunks@toad.com
Subject: real randomness for netscape - user clicking mouse
Message-ID: <Pine.3.89.9509211743.A459-0100000@offshore.com.ai>
MIME-Version: 1.0
Content-Type: text/plain




Jeff Weinstein <jsw@neon.netscape.com> 
>If anyone has specific suggestions I would love to hear them so that we 
>can do a better job. 

Why not just do something similar to what PGP does?  

For netscape you could have a user make circling motions with the mouse
and clicking at random times.  For each click of the mouse you could get a
few bits of randomness from the time, the X position, and the Y position. 
You could get random bits really fast this way. 

You only need to do this the first time a user uses encryption, or you
might just go ahead and force all users to do this as part of starting up
netscape the first time. On subsequent times you use your encryption
algorithm to make your next seed. 

To be safe you could make up two seeds, encrypt each of them to mix them up 
a bit, and then XOR the results together.  A random bit XORed with a non-random bit 
still produces a random bit.  Actually there is probably a better way to just
encrypt each input whole (padding to block size) and XORing as you go along -
that way you would get whatever randomness was there to be had.  Anyway, do something 
so you have as many or more bits of randomness in your seed as there are bits 
in your key or it will still be a weak link in your security chain.

You could even get the randomness during regular mouse use.  Unless the first thing
a user did was try to use encryption I am sure you would have enough by the
time he did use encryption (keep track).

You must get the random bits from something that nobody else could watch. 
Network packets, process IDs, date, time, etc are not secure.  On the
other hand, an attacker would have to have broken the machine to get the
mouse info used above, in which case netscape would have no security no
matter what. 

   --  Vince

PS  I want a free netscape server site license if you use this idea!  :-)