From: Alice Wonder <alice@librelamp•com>
To: bitcoin-dev@lists•linuxfoundation.org
Subject: Re: [bitcoin-dev] SHA1 collisions make Git vulnerable to attakcs by third-parties, not just repo maintainers
Date: Sat, 25 Feb 2017 10:19:11 -0800 [thread overview]
Message-ID: <f309ea73-053d-c3e9-134e-4561e89715f1@librelamp.com> (raw)
In-Reply-To: <CAEM=y+WkgSkc07ZsU6APAkcu37zVZ7dwSc=jAg1nho31S5ZyxQ@mail.gmail.com>
On 02/25/2017 08:10 AM, Ethan Heilman via bitcoin-dev wrote:
>>SHA1 is insecure because the SHA1 algorithm is insecure, not because
> 160bits isn't enough.
>
> I would argue that 160-bits isn't enough for collision resistance.
> Assuming RIPEMD-160(SHA-256(msg)) has no flaws (i.e. is a random
> oracle), collisions can be generated in 2^80 queries (actually detecting
> these collisions requires some time-memory additional trade-offs). The
> Bitcoin network at the current hash rate performs roughly SHA-256 ~2^78
> queries a day or 2^80 queries every four days.
You have to not only produce a ripemd160 collision, you have to produce
a collision that is also a valid sha-256 hash - and that's much much
much more difficult.
next prev parent reply other threads:[~2017-02-25 18:28 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.22137.1487974823.31141.bitcoin-dev@lists.linuxfoundation.org>
2017-02-24 23:49 ` Steve Davis
2017-02-25 1:01 ` Peter Todd
2017-02-25 12:04 ` Steve Davis
2017-02-25 14:50 ` Leandro Coutinho
2017-02-25 16:10 ` Ethan Heilman
2017-02-25 17:45 ` Shin'ichiro Matsuo
2017-02-27 9:15 ` Henning Kopp
2017-02-25 18:19 ` Alice Wonder [this message]
2017-02-25 18:36 ` Ethan Heilman
2017-02-25 19:12 ` Peter Todd
2017-02-25 20:42 ` Watson Ladd
2017-02-25 20:57 ` Peter Todd
2017-02-25 20:53 ` Russell O'Connor
2017-02-25 21:04 ` Peter Todd
2017-02-25 21:21 ` Dave Scotese
2017-02-25 21:34 ` Steve Davis
2017-02-25 21:40 ` Peter Todd
2017-02-25 21:54 ` Steve Davis
2017-02-25 22:14 ` Pieter Wuille
2017-02-25 22:34 ` Ethan Heilman
2017-02-26 6:26 ` Steve Davis
2017-02-26 6:36 ` Pieter Wuille
2017-02-26 7:16 ` Steve Davis
[not found] ` <CAPg+sBirowtHqUT5GUJf9hmDEACKVX19HAon-rrz7GmO8OBsNg@mail.gmail.com>
2017-02-26 16:53 ` Steve Davis
2017-02-25 23:09 ` Leandro Coutinho
2017-02-23 18:14 Peter Todd
2017-02-23 21:28 ` Peter Todd
2017-02-23 23:57 ` Aymeric Vitte
2017-02-24 10:04 ` Tim Ruffing
2017-02-24 15:18 ` Aymeric Vitte
2017-02-24 16:30 ` Tim Ruffing
2017-02-24 17:29 ` Aymeric Vitte
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