Subject: Re: Encrypting RFC822 headers in S/MIME or PGP/MIME messages

From: "Tom Phinney" <[email-masked]>
Date: Thu, 17 Sep 1998 22:33:07 -0700

From: [email-masked]

> > Could (and should) any replacements for RFC2015 and RFC2311 be
amended
> > to allow RFC822 headers to be sent encrypted, and for the
decryption
> > process to swap any encrypted headers found with the corresponding
> > headers in the actual message?
>
> To my best knowledge, there is a non-official scheme to do this. Here
> is an example:
>
> X-PGP-Sig: 2.6.3ia Subject,From,X-Mailer
>        
iQCVAwUBM84wngE7m572a9utAQETEgQAwcL38QVdZbkHuW4Mblmje17deuI85R1j
4yGiDlb1enRDSUyGiLCmk8YphNDiLdKKlMV3Z0opzREUW9Q+sb8fr5s1QXMJhvXs
7hi7s4+V00rjgbqbqXVNiajKiKfVxd7JTRfe0UIZuOljnURP1ZCMlSRD1rDoCEAg
>         1vunQv6QYj4=
>         =hvn0
>
> This is a header field to be stored in a header, mixed with fields to
> be proteced such as Subject, From, and X-Mailer.
>
> If you are interested, I will ack the author to explain his
> experiences.

Of course, there's already a mature technology which uses PGP to 
encapsulate message headers and contents, which replace the original 
message headers and contents after decryption.  It's used in the Type 1

Cypherpunk remailers.  :-)

I'm not proposing that you should use this; it doesn't seem
appropriate.  
But it is worth studying as a reference technology which achieves the 
privacy goals being discussed her.