From: Mike <Michael.Johnson@mejl.com>
Date: Wed, 22 Oct 1997 13:58:07 +0800
To: Eric Murray <ericm@lne.com>
Subject: Re: SMTP Encryption Extension
In-Reply-To: <3.0.3.32.19971021082737.00928b20@localhost>
Message-ID: <3.0.3.32.19971022073807.0099dcb0@localhost>
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Eric Murray wrote:
>Mike writes:
>> Which leads to another idea, couldn't we encrypt SMTP by running it over
>> SSL as a web server cgi? If 99% of Internet traffic is web browsing and we
>> are trying to hide our email, then why not make the email look like web
>> browsing?
>You don't need to run it through a CGI.  There's a port defined for
>SMTP-over-SSL:

Sure, but the idea here was hiding email to defeat traffic analysis. Ssmtp
would raise alarms in any snopper but https would seem like business as
usual, probably just another gif. And https is available through a lot of
firewalls where you can't run ssmtp.

>If you want to protect all email (an excellent idea), build a mail
transport which automatically encrypts each outgoing mail in the key of the
recipient

Eudora/PGP already does that, but you are still quite vulnerable to traffic
analysis unless you add remailers to the pot, which makes it a lot more
complicated and error prone.

A significant threat to online privacy comes from passive attackers,
because you can't do anything about them. If you have an active attacker,
you can analyze his moves and fix the bugs he uses to break root, but a
passive attack is difficult to even detect before it's too late and your
romantic conversations are headline news.


Mike.