From: Bill Stewart <stewarts@ix.netcom.com>
Date: Sun, 2 Jun 1996 18:15:22 +0800
To: cypherpunks@toad.com
Subject: How can you protect a remailer's keys?
Message-ID: <199606020659.XAA25725@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


Encryption is critical for protecting against traffic analysis,
but it's tough to protect a remailer's keys.  Unlike regular email,
where you can type the key in as you read it, remailers need to
run automatically once you set them up.  Some of the choices are:
- leave it around in plaintext with only Unix file protections
        (Ghio2 works this way - does Mixmaster?  My ghio2 version has it 
        compiled into the binary, and I try to delete it from source.)
- type it in to a long-running remailer process 
        (with human intervention to start)
- SSL-based remailers, where the web server handles crypto on
        a per-machine basis instead of per-remailer
- use unauthenticated Diffie-Hellman (either hanging off
        a TCP port somewhere instead of mail, or
        3 pieces of email)
- off-line or off-site remailer such as a POP3 winsock remailer
        that makes it Somebody Else's Problem, and separates
        the remailer's public interface from the working parts
- human intervention on every message (which may not be totally
        worthless for moderated news postings, if you want to
        take that approach to spam prevention.)

Anybody have any other approaches?  These are mostly weak,
annoying, or both.


#				Thanks;  Bill
# Bill Stewart +1-415-442-2215 stewarts@ix.netcom.com
# http://www.idiom.com/~wcs
#				Rescind Authority!