From: Bill Stewart <stewarts@ix.netcom.com>
Date: Wed, 1 Oct 1997 09:59:54 +0800
To: cypherpunks@cyberpass.net
Subject: Re: Remailers and ecash
In-Reply-To: <2321ced0989df8c5fb475134a708618d@anon.efga.org>
Message-ID: <3.0.3.32.19970930161103.006bc934@popd.ix.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain



>And another point: Nobody wants to add latency.  (There may be a few
>applications, but they are rare.)
>What people want is security and one way to get it (sometimes) is by
>adding latency to their messages.

Latency is essential to security, though high volume reduces the latency
that's
needed to get a given level of security.  It's not enough - if your latency
is a
constant, it doesn't buy you anything, and if there's not enough traffic,
the fact that the remailer waited 3 days before sending out the one message it
received doesn't help much either.  But if it's low, and relatively
predictable,
you lose rapidly to traffic analysis instead of potentially losing slowly.

Lucky's point that traffic analysts can learn a lot because messages decrease
in size in type-1 remailer networks is important; Mixmaster's constant-size
message blocks are probably the best way to go (though you then need
more random interblock latency), but the ability to have each remailer
add padding is important if you don't use fixed-size blocks, and I'm not aware
of anybody implementing that.  (The obvious implementation would be for
remailers that randomly pick another remailer to chain through to reach
their destination, since they could put padding inside the encrypted package.)

				Thanks!
					Bill
Bill Stewart, stewarts@ix.netcom.com
Regular Key PGP Fingerprint D454 E202 CBC8 40BF  3C85 B884 0ABE 4639