Date: Sat, 25 Feb 2017 16:40:18 -0500
From: Peter Todd <pete@petertodd.org>
To: Steve Davis <steven.charles.davis@gmail.com>
Message-ID: <20170225214018.GA16524@savin.petertodd.org>
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Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] SHA1 collisions make Git vulnerable to attakcs by
 third-parties, not just repo maintainers
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On Sat, Feb 25, 2017 at 03:34:33PM -0600, Steve Davis wrote:
> Yea, well. I don=E2=80=99t think it is ethical to post instructions witho=
ut an associated remediation (BIP) if you don=E2=80=99t see the potential a=
ttack.

I can't agree with you at all there: we're still at the point where the
computational costs of such attacks limit their real-world impact, which is
exactly when you want the *maximum* exposure to what they are and what the
risks are, so that people develop mitigations.

Keeping details secret tends to keep the attacks out of public view, which
might be a good trade-off in a situation where the attacks are immediately
practical and the need to deploy a fix is well understood. But we're in the
exact opposite situation.

> I was rather hoping that we could have a fuller discussion of what the be=
st practical response would be to such an issue?

Deploying segwit's 256-bit digests is a response that's already fully coded=
 and
ready to deploy, with the one exception of a new address format. That addre=
ss
format is being actively worked on, and could be deployed relatively quickl=
y if
needed.

--=20
https://petertodd.org 'peter'[:-1]@petertodd.org

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