From: Marc.Ringuette@GS80.SP.CS.CMU.EDU
Date: Tue, 29 Dec 92 15:10:54 PST
To: cypherpunks@toad.com
Subject: Re: Self Addressed Stamped Envelopes
Message-ID: <9212292310.AA23801@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


If the remailer is willing to keep some state information around for
a limited time, auto-reply can be even simpler:  when a remailer
forwards mail, it saves the return address and replaces it with a 
unique ID for that mail, which it creates and saves.  The recipient
can just use the 'reply' command of his mailer.  When the remailer
gets mail with this unique ID, it plugs in the old return address, 
encrypts the message to the new destination, and sends it along,
retracing its original path.

This does provide a weaker security guarantee than if the remailer
_throws away_ the correspondence with input and output, though, so
a slightly more complicated alternative is probably better.


-- Marc Ringuette (mnr@cs.cmu.edu)