From: Eli Brandt <ebrandt@jarthur.Claremont.EDU>
Date: Tue, 23 Feb 93 21:20:04 PST
To: cypherpunks@toad.com
Subject: Re: anonymous return addresses
In-Reply-To: <9302240257.AA03919@soda.berkeley.edu>
Message-ID: <9302240519.AA24254@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


> A variant of (1) greatly increases the security.  Have the remailer
> memorize an anonymous return address of type (2).  The information
> that is contained in a remailer then, per pseudonym, is
> 
>   a.  the pseudonym
>   b.  the address of the next remailer to use
>   c.  a block of stuff to be prepended to the outgoing mail.  Presumably
>         this is forwarding instructions for the next remailer.  It would
> 	also be encrypted with the public key of the next remailer.

This is an excellent idea!  It would provide decent security without
forcing J. Random User to figure out how to use the SASE block.
You'd want to have a list of address/SASE pairs to use, choosing
randomly from those that have not yet died.

Oh, a complication.  It would probably be necessary to be able to
add new address/SASEs as they become available, to avoid death of
your pseudonym through cumulative remailer attrition.  But nobody
but the owner can be allowed to add destinations, for obvious
reasons.  The only apparent way to handle this is to require a
password at the time of pseudonym creation.  One-way-hash it, and
require it to add and remove destinations.  It should be
PK-encrypted on its way to the remailer, if possible.  This approach
does not require an identity to be irrevocably tied to a destination
address, interestingly -- you can remove chains to your old address,
and add ones to your new.

Suggestions?  Holes?  Implementations?

> Eric

	 PGP 2 key by finger or e-mail
   Eli   ebrandt@jarthur.claremont.edu