Totally Anonymous Remailing

[Robert J Woodhead <trebor@foretune.co.jp>]

Just toying around with some ideas, and came up with this:

Totally Anonymous Remailing (V1.0)

An "TAR" goes active on the net at site anon.com.
It publishes a Public Key.

1) Creating an anonymous ID.

A User sends message to create-id@anon.com, encrypted with the TAR's
Public key.  The message contains four elements:

	A Public Key generated by the User.
	A Proposed Pseudonym (ie: "Artful-Dodger")
	The Proposed Pseudonym encrypted by the User's Private Key.
	
At this point, the TAR can verify that the new user isn't spoofing
by giving someone else's public key.  It does not reply to the
email message, nor does it store the source (which in any case
could be another anonymous remailer).  If the new Pseudo isn't in
use, it gets allocated.  If it is, it does not.

2) Sending mail to an anonymous ID

Works the same as sending mail to anyone else.  However, on receipt
it is immediately encrypted with the recipients Public key and
placed in a Mail queue.  It is _not_ automatically forwarded.

3) Using an anonymous ID.

The User sends a message to use-id@anon.com, encrypted with the
TAR's Public key.  The message contains the following:

	The User's Pseudonym (ie: "Artful-Dodger@anon.com")
	Command
	Command Specific Parameters

The Command and Parameters are encrypted with the User's private
Key.  This has several nice features that will become apparent
later.

If the command contains errors, or does not decrypt properly, the
anon mailer places an error message into the Pseudonym's mail
queue, but does not otherwise reply.

Commands would be typical:

	MAIL <username(s)>
	{ CC <username(s)>}
	{ BCC <username(s)>}
	{ SUBJECT <whatever>}
	<message>

		Sends <message> using psuedonym.  <messages>
		ought to be encrypted.

	POST <newsgroups(s)>
	SUBJECT <whatever>
	<message>

		Posts <message> using psuedonym.  You could
		verify your pseudo was accepted by posting
		to a worldwide test group.

	SEND <destination>

		Sends accumulated mail, in a batch, to the
		email address specified.  So you can log on
		to any account, even a guest, and get your
		mail.

and so on.  Might be nice to make it a shell on top of something
like MH, and allow you to manage your mailbox remotely and
anonymously.

BTW, none of this double-blind crap.  If someone wants to
reply anonymously, they ought to create their own pseudo.

Anon-net:

Note that use-id@ has a nice property.  Assume there is another
anon server, noname.com, which gets a message, encrypted with
it's public key, that is a command for Artful-Dodger@anon.com.
It can simply re-encrypt the message with anon.com's public key
and pass it on, never having seen the command because it is
encrypted - and only anon.com knows Artful-Dodger's public key,
because Artful only sent it to anon once, encrypted with anon's
key.  The extension - several anon sites passing mail back and
forth regularly (all encrypted batches containing several real
and fake messages) - is obvious and makes traffic analysis
more difficult (especially as the number of sites goes up).

There could also be a facility for one-shot "bounces," the
ability to use the anon site to bounce an email to a restricted
number of addresses (typically, other anon sites).  So you could
email to noname (using noname's key) and have the message bounced
to anon.  So you could have an account on anon and yet never
directly send email to anon -- it would never at any time have
any clue as to your identity.

Of course, you'd have to trust the software.  And some work needs
to be done to ensure the net stays viable even if some of the
sites have been subverted.

This is only a first draft, probably many mistakes.
Comments?