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From: Steve Davis <steven.charles.davis@gmail.com>
In-Reply-To: <CAPg+sBirowtHqUT5GUJf9hmDEACKVX19HAon-rrz7GmO8OBsNg@mail.gmail.com>
Date: Sun, 26 Feb 2017 10:53:29 -0600
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To: Pieter Wuille <pieter.wuille@gmail.com>
Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] SHA1 collisions make Git vulnerable to attakcs by
 third-parties, not just repo maintainers
Precedence: list


> On Feb 26, 2017, at 1:36 AM, Pieter Wuille <pieter.wuille@gmail.com> =
wrote:
>=20
> Typical hash function breaks produce collision attacks, while a =
preimage attack is needed to reduce single-key address security.

Thank you Pieter - that was really helpful. I realize now that I was =
thinking of a preimage attack but had mistakenly assumed that the =
birthday bound applied...

So the unit operation: [genkeypair; =
ripemd160(sha256(pubkey));check_utxoset] would need to be performed =
2.9*10^42 and not (as I had first calculated) 2.4*10^18.=20

Oops. My bad.=