[dns-operations] [DNSOP] DNSSEC threshold signatures idea

[Steve Crocker]

I've been thinking about a version of this problem for several years.
Attached are a short paper and presentation on the topic of a tamperproof
root zone update system.  The ideas are also applicable to other levels in
the DNS tree.

In parallel, there is work on open source hardware crypto that can easily
be extended to include this functionality.

There are some important governance and process details alluded to but not
fleshed out in the paper.  Happy to discuss with anyone interested.

Steve


On Thu, Sep 6, 2018 at 1:34 PM, Hugo Salgado-Hernández <hsalgado at nic.cl>
wrote:

> Hi Mukund.
> I talked about this to Davey in Montreal. There's an implementation
> in github[1] and presentations in OARC[2] and ICANN[3].
>
> I'm not sure if its being used right now in a live zone, but certainly
> in labs and testing. There's been some interests with academic
> institutions, but don't think they're ready yet.
>
> We've been trying to focus this technology as a "poor-man" HSM, as
> having similar security features without buying an expensive HW.
> But I think the root and similar high-value zones will benefit for
> having an split of the private key AND the fact of not needing a
> "root key ceremony" to sign, because you can sign remotely with
> each piece of the private key, and transmit the "signature pieces"
> to a central place.
>
> Hugo
>
> [1] https://github.com/niclabs/docker/tree/master/tchsm
> [2] <https://indico.dns-oarc.net/getFile.py/access?contribId=
> 22&sessionId=3&resId=1&materialId=slides&confId=20>
> [3] <http://buenosaires48.icann.org/en/schedule/wed-dnssec/
> presentation-dnssec-cryptographic-20nov13-en>
>
>
> On 21:42 06/09, Mukund Sivaraman wrote:
> > During a coversation about the Yeti project, Davey Song brought up an
> > idea about using threshold signatures within DNSSEC. While he talked
> > about it primarily for the root zone within the context of having
> > multiple signers for it, I'm curious to know what operators think about
> > the concept for other zones, and if there's any interest in having a
> > working implementation.
> >
> > DNSKEY RRs contain public keys. Corresponding secret keys are managed by
> > signing entities in various ways:
> >
> > * It may be for a low-risk zone and a human may leave the key on the
> >   nameserver itself
> >
> > * The key may be held by some number of trustworthy staff offline and
> >   when signing is required, one of them signs the zone and returns the
> >   signed zone
> >
> > * It may be managed by an automated system under the control of one or
> >   more people
> >
> > * It may be held in a locked computer system which may be accessed when
> >   multiple trustworthy "keepers" are present
> >
> > * There may be schemes like this:
> >   https://www.icann.org/news/blog/the-problem-with-the-seven-keys
> >
> > In many of these cases, it may be possible for one rogue person to sign
> > records against the wish of the rest of the trustworthy group appointed
> > by a zone owner. Even though it's unlikely, it's possible to do so
> > because the control over secret key material may be available to one
> > person, even if it is wrapped in multiple layers.
> >
> > The concept of threshold crypto is that there is a public DNSKEY, for
> > which the secret key is not available in a single form where it can be
> > reconstructed. Instead, N members of a group have some key material each
> > respectively, and any M (< N) members of the group may work together to
> > prepare RRSIGs by using their respective key materials individually, and
> > collaborating to generate the signatures.
> >
> > It may be possible for such a scheme to be compatible with existing
> > DNSSEC algorithms. Is there any operator interest in this?
> >
> >               Mukund
> >
> > _______________________________________________
> > DNSOP mailing list
> > DNSOP at ietf.org
> > https://www.ietf.org/mailman/listinfo/dnsop
> >
>
> _______________________________________________
> DNSOP mailing list
> DNSOP at ietf.org
> https://www.ietf.org/mailman/listinfo/dnsop
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.dns-oarc.net/pipermail/dns-operations/attachments/20180906/ef8f8ec3/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Proposal for a Tamperproof RZM 2017-10-16.docx
Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
Size: 163496 bytes
Desc: not available
URL: <https://lists.dns-oarc.net/pipermail/dns-operations/attachments/20180906/ef8f8ec3/attachment.docx>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Tamperproof 2017-10-16.pptx
Type: application/vnd.openxmlformats-officedocument.presentationml.presentation
Size: 85707 bytes
Desc: not available
URL: <https://lists.dns-oarc.net/pipermail/dns-operations/attachments/20180906/ef8f8ec3/attachment.pptx>