Subject: Re: [bitcoin-dev] We need to fix the block withholding attack

From: Chris Priest <[email-masked]>
Date: Sat, 19 Dec 2015 19:47:12 -0800

On 12/19/15, jl2012 <[email-masked]> 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.