Subject: [TLS] Re: [lamps] TLS Client Certificates; a survey
From: Alan DeKok <[email-masked]>
To: [email-masked]
Cc: Tomas Gustavsson <[email-masked]>, Michael Richardson <[email-masked]>, Tls <[email-masked]>, "[email-masked]" <[email-masked]>
Date: Tue, 24 Mar 2026 09:25:42 +1300
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>

On Mar 24, 2026, at 8:18 AM, Jeffrey Walton <[email-masked]> wrote:
> Regarding Item (2), wouldn't Trust on First Use (TOFU) work well?

  Sure, for some definition of "work".  The traffic would be more secure than using raw TCP.

  But there are questions remaining.  Is the server you're connecting to actually owned by example.com <http://example.com/>?  Is it authorized?  etc.  We just don't know.

>   Remember, TLS is only intended to be about as secure as brick-and-mortar stores.  It is not intended to be as secure as Fort Knox.  The biggest threat in mail systems seems to be the mail operator reading your messages.  That's the insider threat in brick-and-mortar stores, where employees are committing an equal amount of the theft as external customers.
> 
> And who needs a CA anyways?  All we need is a hostname and a public key.  We don't need a CA to bind them.  The hostname and public key information is presented in an end-entity certificate, so that's all we need.  The self-signed certificate can be hosted in DNS and retrieved as required since that seems to be the modern equivalent to the X.500 directory.  The world does not need to be adverse to self-signed certificates just because the CA/BF does not care for them.

  I find it a bit surprising that certificates can carry a substantial amount of information about purposes, authorization, hierarchies, etc.  But that pretty much the only way to make them usable is to just ignore all of that.

  Alan DeKok.