MIME-Version: 1.0
Sender: nbvfour@gmail.com
In-Reply-To: <219f125cee6ca68fd27016642e38fdf1@xbt.hk>
References: <20151219184240.GB12893@muck>
	<CAAcC9yvh2ma2dFhNDEKs7vfXyQF9L+T0YtRvOsJ15AbfVti=cw@mail.gmail.com>
	<219f125cee6ca68fd27016642e38fdf1@xbt.hk>
Date: Sat, 19 Dec 2015 19:47:12 -0800
Message-ID: <CAAcC9ys_t7X0WpQ8W3577M8GLiA5sPV2F1BJ9qZbnMkE-1j3+Q@mail.gmail.com>
From: Chris Priest <cp368202@ohiou.edu>
To: jl2012 <jl2012@xbt.hk>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Cc: bitcoin-dev@lists.linuxfoundation.org
Subject: Re: [bitcoin-dev] We need to fix the block withholding attack
Precedence: list

On 12/19/15, jl2012 <jl2012@xbt.hk> wrote:
> Chris Priest via bitcoin-dev =E6=96=BC 2015-12-19 22:34 =E5=AF=AB=E5=88=
=B0:
>> 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.