From: Andy Dustman <andy@CCMSD.chem.uga.edu>
Date: Fri, 8 Aug 1997 15:38:18 +0800
To: Adam Back <aba@dcs.ex.ac.uk>
Subject: Re: disposable remailers (was Re: Eternity Uncensorable?)
In-Reply-To: <199708072250.XAA05978@server.test.net>
Message-ID: <Pine.LNX.3.94.970807200648.2843J-100000@neptune.chem.uga.edu>
MIME-Version: 1.0
Content-Type: text/plain



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On Thu, 7 Aug 1997, Adam Back wrote:

> Wasn't there for a time a hidden middleman.  That is a middleman
> remailer who's published address was a nym account on a nymserver?
> That'd be a "hidden middleman".

There's some now. medusa@squirrel.owl.de is one.  middleman@cyberpass.net
(reno) might be another (not sure the account is anonymous, but could be).

> Dimitri suggested on cypherpunks in the last round of discussion of
> this sort of thing another variation on that -- that you could deliver
> the mail if the person had a PGP public key on the keyservers --
> whether the email was encrypted or not.  On the assumption that people
> who use PGP would be unlikley to complain of anonymous mail.

The only problem with that is the denial-of-service attack you describe
below. I figure if it's already encrypted, delivery is likely to be
welcomed rather than irritating.

> He also suggested beefing up keyserver submission checks (there are
> none right now) so that you need a replyable address to submit a key,
> otherwise the remailer-baiter just posts a key generated with their
> "victim's" email address on it prior to sending to them.

Yeah, I had in mind some kind of magic cookie exchange using the submitted
key. Once the cookie gets returned, the keyserver signs the key with a
special signing key which certifies that the key has at least passed the
"cookie exchange" test. The remailer I was working on (I say "was" because
I just have been too darn busy to finish it) would have implemented that
very thing. It's essentially the same thing the nymservers do when
configured to confirm reply blocks, which they always are. 

Back to the subject: Disposable remailers. It seems the juno remailer
software would be good for this. I'm not sure what the sign-up requirement
are, but it's free. I was also thinking about web-based free mail
services, such as Hotmail and Rocketmail. Receiving mail means having to
parse some HTML, which from the looks of things is do-able but not
trivial. Sending mail might be easier to implement.

Which brings up an interesting idea for an exitman/middleman remailer: Use
a nym or commercial ISP to receive the mail, use throwaway free mail
accounts for delivery (maybe even just plaintext delivery). Hotmail, at
least, inserts an X-Originating-IP:  header, though.  I expect others do
the same. So put your remailer output on a ZIP disk or floppy and run your
delivery on whatever public or semi-public access machine you happen to
get your hands on, once or twice a day.

Andy Dustman / Computational Center for Molecular Structure and Design / UGA
    To get my PGP public key, send me mail with subject "send file key".
For the ultimate anti-spam procmail recipe, send me mail with subject "spam"
"Encryption is too important to leave to the government."  -- Bruce Schneier
http://www.ilinks.net/~dustman    mailto:andy@CCMSD.chem.uga.edu      <}+++<



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