public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Tristan Hoy <tristan.hoy@gmail.com>
To: Tim Ruffing <tim.ruffing@mmci.uni-saarland.de>,
	 Bitcoin Protocol Discussion
	<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Transition to post-quantum
Date: Tue, 13 Feb 2018 08:32:35 +1100	[thread overview]
Message-ID: <CAFEpHQHYdE3m2GUtN=ijvtYUudwtcG52rRxzH66VFbgO1KEihw@mail.gmail.com> (raw)
In-Reply-To: <1518450650.7829.87.camel@mmci.uni-saarland.de>

[-- Attachment #1: Type: text/plain, Size: 3065 bytes --]

Hi Tim,

Just read through your post, thanks for the heads up - I only just joined
this mailing list.

In a post-quantum world, your second "d" type transaction is completely
forgeable, which means it is vulnerable to front-running. An adversary
capable of breaking ECDSA needs only listen for these transactions, obtain
"classic_sk" and then use a higher fee (or relationship with a miner) to
effectively turn your original "d" transaction into a double-spend, with
the forged transaction sending all your funds to the adversary.

I'm pretty confident that a PQ DSA is required to prevent front-running,
and that no "commit-reveal" scheme will be secure without one.

The other issue with your approach is that if it is rolled out today, it
will effectively double transaction volumes - this is what I tried to solve
in solutions 2 and 3 in my article by instead modifying the address
generation process.

Regards,

Tristan

On Tue, Feb 13, 2018 at 2:50 AM, Tim Ruffing via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> Hi Tristan,
>
> Regarding the "Post-Quantum Address Recovery" part (I haven't read the
> other parts), you may be interested in my message to the list from last
> month and the rest of the thread:
> https://lists.linuxfoundation.org/pipermail/bitcoin-dev/
> 2018-January/015659.html
>
> This is an approach which aims to avoid the issues that you've
> mentioned in your blog post.
>
> Best,
> Tim
>
> On Tue, 2018-02-13 at 01:13 +1100, Tristan Hoy via bitcoin-dev wrote:
> > Hi all,
> >
> > Recently I've been exploring what a post-quantum attack on Bitcoin
> > would actually look like, and what options exist for mitigating it.
> >
> > I've put up a draft of my research here: https://medium.com/@tristanh
> > oy/11271f430c41
> >
> > In summary:
> > 1) None of the recommended post-quantum DSAs (XMSS, SPHINCS) are
> > scalable
> > 2) This is a rapidly advancing space and committment to a specific
> > post-quantum DSA now would be premature
> > 3) I've identified a strategy (solution 3 in the draft) that
> > mitigates against the worst case scenario (unexpectedly early attack
> > on ECDSA) without requiring any changes to the Bitcoin protocol or
> > total committment to a specific post-quantum DSA that will likely be
> > superseded in the next 3-5 years
> > 4) This strategy also serves as a secure means of transferring
> > balances into a post-quantum DSA address space, even in the event
> > that ECDSA is fully compromised and the transition is reactionary
> >
> > The proposal is a change to key generation only and will be
> > implemented by wallet providers.
> >
> > Feedback would be most appreciated.
> >
> > Regards,
> >
> > Tristan
> > _______________________________________________
> > bitcoin-dev mailing list
> > bitcoin-dev@lists.linuxfoundation.org
> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

[-- Attachment #2: Type: text/html, Size: 4487 bytes --]

  reply	other threads:[~2018-02-12 21:32 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-12 14:13 [bitcoin-dev] Transition to post-quantum Tristan Hoy
2018-02-12 15:50 ` Tim Ruffing
2018-02-12 21:32   ` Tristan Hoy [this message]
2018-02-13  6:46     ` Tim Ruffing
2018-02-13 10:06       ` Tristan Hoy
2018-02-15 15:59         ` Tim Ruffing
2018-02-15 20:27           ` Natanael
2018-02-15 21:57             ` Tim Ruffing
2018-02-15 22:44               ` Natanael
2018-02-15 22:45                 ` Natanael
2018-02-15 23:44                 ` Tim Ruffing
2019-10-24 15:34                   ` Erik Aronesty

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAFEpHQHYdE3m2GUtN=ijvtYUudwtcG52rRxzH66VFbgO1KEihw@mail.gmail.com' \
    --to=tristan.hoy@gmail.com \
    --cc=bitcoin-dev@lists.linuxfoundation.org \
    --cc=tim.ruffing@mmci.uni-saarland.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox