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From: jl2012 <jl2012@xbt•hk>
To: Chris Priest <cp368202@ohiou•edu>
Cc: bitcoin-dev@lists•linuxfoundation.org, nbvfour@gmail•com
Subject: Re: [bitcoin-dev] We need to fix the block withholding attack
Date: Sat, 19 Dec 2015 23:24:52 -0500	[thread overview]
Message-ID: <aff8da46a69bdd7ef92ca87725866a5c@xbt.hk> (raw)
In-Reply-To: <CAAcC9ys_t7X0WpQ8W3577M8GLiA5sPV2F1BJ9qZbnMkE-1j3+Q@mail.gmail.com>

Chris Priest 於 2015-12-19 22:47 寫到:
> On 12/19/15, jl2012 <jl2012@xbt•hk> wrote:
>> Chris Priest via bitcoin-dev 於 2015-12-19 22:34 寫到:
>>> Block witholding attacks are only possible if you have a majority of
>>> hashpower. If you only have 20% hashpower, you can't do this attack.
>>> Currently, this attack is only a theoretical attack, as the ones with
>>> all the hashpower today are not engaging in this behavior. Even if
>>> someone who had a lot of hashpower decided to pull off this attack,
>>> they wouldn't be able to disrupt much. Once that time comes, then I
>>> think this problem should be solved, until then it should be a low
>>> priority. There are more important things to work on in the meantime.
>>> 
>> 
>> This is not true. For a pool with 5% total hash rate, an attacker only
>> needs 0.5% of hash rate to sabotage 10% of their income. It's already
>> enough to kill the pool
>> 
>> 
> 
> This begs the question: If this is such a devastating attack, then why
> hasn't this attack brought down every pool in existence? As far as I'm
> aware, there are many pools in operation despite this possibility.

It did happen: 
https://www.reddit.com/r/Bitcoin/comments/28242v/eligius_falls_victim_to_blocksolution_withholding/

The worst thing is that the proof for such attack is probabilistic, not
deterministic.

A smarter attacker may even pretend to be many small miners, make it
even more difficult or impossible to prove who are attacking.


> Then shouldn't this be something the pool deals with, not the bitcoin 
> protocol?

The only solution is to ask for KYC registration, unless one could 
propose
a cryptographic solution that does not require a consensus fork.



  reply	other threads:[~2015-12-20  4:24 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-19 18:42 Peter Todd
2015-12-19 19:30 ` Bob McElrath
2015-12-19 20:03 ` jl2012
2015-12-20  3:34 ` Chris Priest
2015-12-20  3:36   ` Matt Corallo
2015-12-20  3:43     ` Chris Priest
2015-12-20  4:44       ` Peter Todd
2015-12-26  8:12         ` Multipool Admin
2015-12-27  4:10           ` Geir Harald Hansen
2015-12-28 19:12           ` Peter Todd
2015-12-28 19:30             ` Emin Gün Sirer
2015-12-28 19:35               ` Multipool Admin
2015-12-28 19:33             ` Multipool Admin
2015-12-28 20:26             ` Ivan Brightly
2015-12-29 18:59               ` Dave Scotese
2015-12-29 19:08                 ` Jonathan Toomim
2015-12-29 19:25                 ` Allen Piscitello
2015-12-29 21:51                   ` Dave Scotese
2015-12-20  3:40   ` jl2012
2015-12-20  3:47     ` Chris Priest
2015-12-20  4:24       ` jl2012 [this message]
2015-12-20  5:12         ` Emin Gün Sirer
2015-12-20  7:39           ` Chris Priest
2015-12-20  7:56             ` Emin Gün Sirer
2015-12-20  8:30               ` Natanael
2015-12-20 11:38           ` Tier Nolan
2015-12-20 12:42             ` Natanael
2015-12-20 15:30               ` Tier Nolan
2015-12-20 13:28           ` Peter Todd
2015-12-20 17:00             ` Emin Gün Sirer
2015-12-21 11:39               ` Jannes Faber
2015-12-25 11:15                 ` Ittay
2015-12-25 12:00                   ` Jonathan Toomim
2015-12-25 12:02                   ` benevolent
2015-12-25 16:11                   ` Jannes Faber
2015-12-26  0:38               ` Geir Harald Hansen
2015-12-28 20:02               ` Peter Todd
2015-12-26  8:23             ` Eric Lombrozo
2015-12-26  8:26               ` Eric Lombrozo
2015-12-26 15:33               ` Jorge Timón
2015-12-26 17:38                 ` Eric Lombrozo
2015-12-26 18:01                   ` Jorge Timón
2015-12-26 16:09               ` Tier Nolan
2015-12-26 18:30                 ` Eric Lombrozo
2015-12-26 19:34                   ` Jorge Timón
2015-12-26 21:22               ` Jonathan Toomim
2015-12-27  4:33                 ` Emin Gün Sirer

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