From: Matthew J Ghio <mg5n+@andrew.cmu.edu>
Date: Wed, 13 Oct 93 16:02:16 PDT
To: gg@well.sf.ca.us>
Subject: Re: Spread-spectrum net (vulnerability of)
In-Reply-To: <93Oct13.033350pdt.13932-3@well.sf.ca.us>
Message-ID: <ogj8WPO00awIJRBV5g@andrew.cmu.edu>
MIME-Version: 1.0
Content-Type: text/plain


> "a sort of virtual-space map, which would reveal
> nothing about actual phyical location of the sites
> or the person you are contacting."
>
> I'm not so sure... in cellular systems, cells must know where the handsets
> are located in order to send incoming calls.  Your transmitter has a
> physical location which could presumably be tracked in the normal manner,
> and I would expect the overall routing information in a net to be
> susceptible to traffic analysis in any case.  An individual who is using the
> system to communicate wouldn't be able to find the physical address of
> another user, but e.g. an intelligence agency which was looking at the
> entire network would.

You've hit the key concept - motion.  If you are operating from a fixed
transmitter, finding locations is very difficult.  The problem is that
if someone was to drive around the city in a radio equipped truck, and
log into lots of different nodes, they could at least get a partial map
of where various nodes are located.  This could be countered by
additional software which would emulate the node you logged in on even
tho it actually switched you to another node (you communicate with a
virtual fixed node which may or may not be the actual one you are
communicating with).  hmm...  Which leaves us with the problem of
developing software to do that, and developing some method of logging
into the system which would not be node-specific (if you had to do
something special for each node, it would immediately reveal what areas
the nodes were in.)  That creates the problem of developing something
that is not a plainly obvious "log-in" signal that the FCC could look
for.  Ideas?