From: "Luke-Jr" <luke@dashjr•org>
To: bitcoin-development@lists•sourceforge.net
Subject: Re: [Bitcoin-development] Difficulty adjustment / time issues
Date: Tue, 13 Sep 2011 12:48:29 -0400 [thread overview]
Message-ID: <201109131248.32502.luke@dashjr.org> (raw)
In-Reply-To: <CABsx9T2XLj4gZVPYodteaVCm0chR1n4WLUoSqB6+NnmWCDqHKQ@mail.gmail.com>
On Tuesday, September 13, 2011 11:06:37 AM Gavin Andresen wrote:
> Fixing (2) is easier; incorporating a ntp library and/or simply
> removing the bitcoin mining code from the client but requiring pools
> and miners to have accurate-to-within-a-minute system clocks (or their
> blocks will be "discouraged") seems reasonable to me. If you want to
> produce blocks that the rest of the network will accept, run ntp on
> your system.
This is not currently reasonable. Rolling extranonce is not efficient, and
using it to generate work for 400+ GH/s worth of miners every new block
(longpoll) can easily take seconds. Noncerange helps a little, but has poor
support presently, and still requires an otherwise-unique work per 4 GH/s.
That only leaves pools with the time header to play with. Furthermore, within-
a-minute accuracy basically forces all miners to rollntime-- I'm not against
this result, but it does mean many miners and pools will be left out in the
cold.
> I THINK that fixing (2) will make (1) a non-issue-- if miners can't
> mess around with block times very much then it will be very difficult
> for them to manipulate the difficulty for their benefit.
Miners already have very limited area to mess around with block times.
My understanding of these attacks is that they somehow bypass the limitations
in place.
next prev parent reply other threads:[~2011-09-13 16:48 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-13 15:06 Gavin Andresen
2011-09-13 15:15 ` Vladimir Marchenko
2011-09-13 15:54 ` John Smith
2011-09-13 16:24 ` kjj
2011-09-14 14:45 ` Gavin Andresen
2011-09-14 15:43 ` Luke-Jr
2011-09-14 16:06 ` Christian Decker
2011-09-14 19:52 ` Aidan Thornton
2011-09-14 20:09 ` Gregory Maxwell
2011-09-14 20:28 ` Gavin Andresen
2011-09-14 21:36 ` Alex Waters
2011-09-14 21:51 ` Gregory Maxwell
2011-09-14 22:07 ` theymos
2011-09-14 23:01 ` Luke-Jr
2011-09-13 16:48 ` Luke-Jr [this message]
2011-09-14 21:45 ` theymos
2011-11-07 15:02 ` Pieter Wuille
2011-11-07 15:27 ` Luke-Jr
2011-11-07 15:43 ` Pieter Wuille
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