What email encryption is actually in use?

Jeremey Barrett jeremey at rot26.com
Wed Oct 2 13:50:37 EDT 2002

Matthew Byng-Maddick wrote:
| On Wed, Oct 02, 2002 at 10:04:03AM -0500, Jeremey Barrett wrote:
|>BTW, most and probably all of the major mail clients out there will do
|>STARTTLS *for SMTP*. It's a matter of servers offering it and clients
|>being configured to actually use it. It'd be nice if they always used it
|>if it's available, but right now I think they all require being told to.
| I have to say that much as it is a laudable goal to get widespread
| encryption on the SMTP server network, I'm rapidly coming to the
| that opportunistic encryption in this way doesn't really work. Consider
| where one side believes that it will only accept certificates signed by a
| particular CA (a perfectly plausible scenario in the case of SSL/TLS), and
| I hand it a self-signed one - this is not communicable before the
| starts up, and in-protocol, a failure to apply policy causes the
| to be shut down (this is by no means the only one, consider one side that
| only use DES and the other that never use it), leaving the connection
in an
| undefined state.

Opportunistic SSL/TLS will only work if people configuring it are of the
mind that it's better to encrypt than not. No public SMTP server should
require valid certificates or give any more trust over SSL than they do
over not-SSL. This way, the links get encrypted.

Anything else (on public SMTP servers) is misconfiguration. Now you
could *add* trust, as appropriate, if you do see certs (or whatever)
that you like, but it's always better to encrypt than not, even if
no additional trust is gained.

Jeremey Barrett [jeremey at rot26.com]    Key: http://rot26.com/gpg.asc
GnuPG fingerprint: 716E C811 C6D9 2B31 685D 008F F715 EB88 52F6 3860

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