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From: Melvin Carvalho <melvincarvalho@gmail.com>
To: Will <will@phase.net>
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] bitcoin pull requests
Date: Tue, 2 Apr 2013 00:27:51 +0200	[thread overview]
Message-ID: <CAKaEYh+bePsmzM5XU1wpb_SFrTnbKB8LxMvWLLqP4p8KuesuSA@mail.gmail.com> (raw)
In-Reply-To: <CAHQs=o4pKBoVO-14dqoq9EoNxq2BNnKE+zmOjLBw+XqJfAp8yA@mail.gmail.com>

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On 2 April 2013 00:10, Will <will@phase.net> wrote:

> The threat of a SHA1 collision attack to insert a malicious pull request
> are tiny compared with the other threats - e.g. github being compromised,
> one of the core developers' passwords being compromised, one of the core
> developers going rogue, sourceforge (distribution site) being compromised
> etc etc... believe me there's a lot more to worry about than a SHA1
> attack...
>
> Not meaning to scare, just to put things in perspective - this is why we
> all need to peer review each others commits and keep an eye out for
> suspicious commits, leverage the benefits of this project being open source
> and easily peer reviewed.
>

Very good points, and I think you're absolutely right.

But just running the numbers, to get the picture, based of scheiner's
statistics:

http://www.schneier.com/blog/archives/2012/10/when_will_we_se.html

We're talking about a million terrahashes = 2^60 right?

With the block chain, you only have a 10 minute window, but with source
code you have a longer time to prepare.

Couldnt this be done with an ASIC in about a week?



>
> Will
>
>
> On 1 April 2013 23:52, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
>
>>
>>
>>
>> On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrote:
>>
>>> An attacker would have to find a collision between two specific pieces
>>> of code - his malicious code and a useful innoculous code that would be
>>> accepted as pull request. This is the second, much harder case in the
>>> birthday problem. When people talk about SHA-1 being broken they actually
>>> mean the first case in the birthday problem - find any two arbitrary values
>>> that hash to the same value. So, no I don't think it's a feasible attack
>>> vector any time soon.
>>>
>>> Besides, with that kind of hashing power, it might be more feasible to
>>> cause problems in the chain by e.g. constantly splitting it.
>>>
>>
>> OK, maybe im being *way* too paranoid here ... but what if someone had
>> access to github, could they replace one file with one they had prepared at
>> some point?
>>
>>
>>>
>>>
>>> On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
>>>
>>>>  I was just looking at:
>>>>
>>>> https://bitcointalk.org/index.php?topic=4571.0
>>>>
>>>> I'm just curious if there is a possible attack vector here based on the
>>>> fact that git uses the relatively week SHA1
>>>>
>>>> Could a seemingly innocuous pull request generate another file with a
>>>> backdoor/nonce combination that slips under the radar?
>>>>
>>>> Apologies if this has come up before ...
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>>>> Rise to greatness in Intel's independent game demo contest.
>>>> Compete for recognition, cash, and the chance to get your game
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>>>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>>>> _______________________________________________
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>>>>
>>>>
>>>
>>
>>
>> ------------------------------------------------------------------------------
>> Own the Future-Intel&reg; Level Up Game Demo Contest 2013
>> Rise to greatness in Intel's independent game demo contest.
>> Compete for recognition, cash, and the chance to get your game
>> on Steam. $5K grand prize plus 10 genre and skill prizes.
>> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
>> _______________________________________________
>> Bitcoin-development mailing list
>> Bitcoin-development@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>>
>>
>

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  reply	other threads:[~2013-04-01 22:27 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-01  8:26 [Bitcoin-development] bitcoin pull requests Melvin Carvalho
2013-04-01 18:28 ` Petr Praus
2013-04-01 21:52   ` Melvin Carvalho
2013-04-01 22:10     ` Will
2013-04-01 22:27       ` Melvin Carvalho [this message]
2013-04-01 22:51         ` Roy Badami
2013-04-01 22:54           ` Roy Badami
2013-04-03  3:41             ` Wladimir
2013-04-03  3:51               ` Jeff Garzik
2013-04-03 15:52                 ` grarpamp
2013-04-03 16:05                   ` Gavin Andresen
2013-04-03 16:23                     ` grarpamp
     [not found]                       ` <CAAS2fgT06RHBO_0stKQAYLPB39ZAzaCVduFZJROjSzXUP4Db+g@mail.gmail.com>
2013-04-03 18:12                         ` grarpamp
2013-04-04  9:11                           ` Mike Hearn
2013-04-04 10:04                             ` Mike Hearn

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