From: George A. Gleason <gg@well.sf.ca.us>
Date: Tue, 27 Oct 92 02:39:00 PPE
To: shipley@tfs.COM
Subject: Re: Alpha Particles and One Time Pads
Message-ID: <199210270938.AA27715@well.sf.ca.us>
MIME-Version: 1.0
Content-Type: text/plain


Re Pete's proposal for an on-net random source which could be accessible to
users who would then use a psuedo-random process to select which bits to use
in compiling cypher keys:

What you'll get will be superencipherment, which is no more secure than the
links in the chain.  The random stream would be non-secure; and so we're
left with the security of the psuedo-random selection process.  

To analogise somewhat, white noise put through a filter has the
characteristics of the filter.  Try it with FM static and a graphic
equaliser.  

Now to play devil's advocate here, I wonder if a less-than-perfect physical
random source would be acceptable, since the potential domain of decryptions
would be large enough that unicity in cryptanalysis would in practice be
unattainable.  What do you think...?