From: Hal <74076.1041@CompuServe.COM>
Date: Mon, 4 Jan 93 23:41:21 PST
To: CYPHERPUNKS <CYPHERPUNKS@TOAD.COM>
Subject: Re: Remail addresses...
Message-ID: <930105070855_74076.1041_DHJ43-1@CompuServe.COM>
MIME-Version: 1.0
Content-Type: text/plain


-----BEGIN PGP SIGNED MESSAGE-----

From: edgar@spectrx.Saigon.COM (Edgar W. Swank)
>
>         Anon-To: <next destination>
>         Encrypt-With: <some DES or IDEA key>
> 
> I'd like to point out that the "-ca" function of PGP could be used
> to perform this function if Encrypt-With: specified a PGP pass-phrase
> rather than a direct key.

This sounds like a good idea.  The user would have to have some
scripts to decrypt incoming anonymous-address messages using this
pass phrase (or some sequence of pass phrases if more than one
remailer was used for the anonymous address).

> I'd also like to suggest that the message-
> body to be encrypted require heading and trailing delimiters such as:
>  
> -----BEGIN MESSAGE BODY-----
> -----END MESSAGE BODY-----
>  
> Note delimiters would not be part of message body and would not
> be encrypted.

These anonymous addresses do need a distinction between the "message
address" (or "envelope") and the message body.  The anonymous address
gets decrypted at each step, and the message body gets encrypted
at each step using the scheme above.

But Eric Hughes pointed out that we already have such a distinction
in the RFC822 message headers vs body.  We should use that existing
structure rather than try to create our own.  That means that anonymous
addresses should be designed to fit into mail headers.  Unfortunately
many mail agents make this difficult or inconvenient right now, but
perhaps that is an area where we could make some improvements.

In this model, we would not need message body delimiters, since mail
already has its message body delimited distinct from its headers.

If we do process the message body with encryption at each stage,
I do have an idea which could be useful.  If the body which is
being encrypted is already in the format of an ASCII-encoded message
using the standard RFC822 encryption used in PGP, RIPEM and PEM,
then rather than just encrypting it it could be de-ASCII'd, then
encrypted, then re-ASCII'd.  This would keep it from increasing
in size by a factor of 4/3 at each encryption step.

Hal

-----BEGIN PGP SIGNATURE-----
Version: 2.1

iQCVAgUBK0kHvKgTA69YIUw3AQHBuwP/ekp1feh06tLHwxws49DE3wVxnu/36Yg7
oW2l43n3llgRJC+r/KYJ2+5LTG0/f1Ib/R8c4qxUJzZeCj7zABSdJ6KSwIlwmfP6
Djz0vOBnife6CvhQRi+T/8NuFqFIzlxO1vK+7tG9KWshxP+7AMayGOLuY0pOTREX
7brcJHnn7Mg=
=9Uss
-----END PGP SIGNATURE-----


Distribution:
  CYPHERPUNKS >INTERNET:CYPHERPUNKS@TOAD.COM