Re: [dns-privacy] what's good enough, or Threat Model

[Eric Rescorla <[e-mail]>]

On Sat, Nov 2, 2019 at 4:47 PM John Levine <[e-mail]> wrote:

> In article <CABcZeBOBFFi=
> [e-mail]> you write:
> >Conversely, what made opportunistic style approaches viable for
> >SMTP was that there was an existing protocol handshake that
> >could be conveniently adopted to have upward negotiation (STARTTLS). ...
>
> >In this case, I think the relevant question is whether there is some
> >viable mechanism (by which I mean one that people might actually
> >use) by which recursive resolvers would, in talking to an authoritative
> >resolver, detect that that resolver supported secure transport and
> >upgrade.
>
> It's easy enough to imagine an EDNS option that asks whether a server
> supports ADoT, that the client can use as a signal to try again on
> port 853.


Sure. One reason you might be sad about this is that it has an extra round
trip.



> PS: there's always dnscurve
>

Sure. Dnscurve is a variant of the "have a secure reference" approach.

-Ekr