Re: [Ntp] Draft extension NTS for pools

[Miroslav Lichvar <[e-mail]>]

On Fri, Jan 12, 2024 at 09:11:32AM +0100, David Venhoek wrote:
> We chose not to go that route for two reasons:
> 
> 1) it wouldn't actually be enough to just exchange server keys and
> standardize that. This would mean standardizing the format and
> cryptographic algorithms used in encoding the cookies for the ntp
> client as well. That is significantly more involved both in actually
> implementing the changes, as well as standardizing it. This would
> involve significantly more opinionated choices than the current
> proposal. In particular, it would remove a lot, if not all, of the
> cryptographic agility the suggestion we made has.

Ok, makes sense. It would help to explain it in the draft, why the
more obvious solutions were not chosen.

> Furthermore, given
> the fact that hardware implementations already exist for the cookie
> parsing and that these tend to be much harder to change on this point,
> this would effectively lock out those implementations.

Oh, there is already an ASIC implementation of NTS?

> 2) Although subtle, and in some cases of debatable value, there is a
> minor gain in security with the current setup, in that the pool cannot
> decode any of the cookies used by the individual pool servers.

The pool can always provide its own cookies and NTP server, so I'm not
sure if this really makes a difference.

-- 
Miroslav Lichvar