On Thu, 09 Oct 2014 20:01:47 -0400, Warren Kumari wrote: 
>Hi there all,
>
>So, DPRIVE should be meeting in Hawaii, either as a fully fledged
>working group, or like a BoF that we are planning on running like a WG
>session.
>...
>
>One agenda request -- is there anyone who is knowledgeable on DNSCurve
>and can explain clearly and in baby words (suitable for the likes of
>me) why this doesn't solve all our problems? Perhaps we can be the
>worlds shortest WG :-)

We talk about this issue, comparing DNSCurve and DNSCrypt [*] in a
section 3.2 of our tech report about T-DNS (one of the DNS-over-TLS
proposals).  (The tech report is at
http://www.isi.edu/~johnh/PAPERS/Zhu14b/ .)

My summary of what we wrote there:

My biggest concern is that dnscurve/dnscrypt are bespoke for DNS.

That's good and bad.  The good is that it is very focused and has no
"fat" for DNS.

But for a long-lived standard, I think one wants something that lets you
choose the crypto protocols, and change that choice with relative ease
in the future.  (Without taking a position on ECC here, I'm saying that
NO single protocol should be locked in.) [**]

Given the subtlety of crypto design and implementation issues, I also
think using an off-the-shelf design (like TLS) and with multiple, mature
implementations has a big advantage over rolling one's one. [***]

Finally, dnscurve requires that the key go in the hostname of the
server.  For some, that's a downside, ranging from unpleasant to perhaps
operationally impossible.

There are also a bunch of pragmatic questions: are there draft specs for
dnscrypt and dnscurve?  multiple implementations?  has IETF documented
ECC yet?  These can all be fixed with work, but it's not just
off-the-shelf.

But to me the core question is: is DNS really so special we
want have design our own, new, protocol?  Or can we follow what HTTP and
SMTP and POP and IMAP do?

   -John


[*] DNSCrypt is stub-to-recursive, and DNSCurve is
recursive-to-authoritative, they're similar but different.  I'll let an
expert in them describe how they compare.

[**] Yes choice of protocol raises complexity and risk of downgrade
attacks, but one must compare that against the cost of swapping out a
hard-coded choice.

[***] Clearly the the recent bugs in openssl and gnutls are serious, so
standard designs and common libraries is not a panacea.  I think the
vetting of a common design and the attention common libraries get remain
hugely valuable.

_______________________________________________
dns-privacy mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/dns-privacy

Reply via email to