Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YqY2K-00086f-Kr for bitcoin-development@lists.sourceforge.net; Fri, 08 May 2015 02:29:12 +0000 X-ACL-Warn: Received: from mout.perfora.net ([74.208.4.194]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1YqY2J-0006nx-2W for bitcoin-development@lists.sourceforge.net; Fri, 08 May 2015 02:29:12 +0000 Received: from mail-qc0-f174.google.com ([209.85.216.174]) by mrelay.perfora.net (mreueus001) with ESMTPSA (Nemesis) id 0MWRTQ-1YkZfD0N4c-00XmTc for ; Fri, 08 May 2015 04:16:13 +0200 Received: by qcbgy10 with SMTP id gy10so30948307qcb.3 for ; Thu, 07 May 2015 19:16:12 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.55.20.30 with SMTP id e30mr3551292qkh.45.1431051372561; Thu, 07 May 2015 19:16:12 -0700 (PDT) Received: by 10.96.111.134 with HTTP; Thu, 7 May 2015 19:16:12 -0700 (PDT) Received: by 10.96.111.134 with HTTP; Thu, 7 May 2015 19:16:12 -0700 (PDT) In-Reply-To: <20150507220848.GK63100@giles.gnomon.org.uk> References: <20150507200023.GI63100@giles.gnomon.org.uk> <20150507214200.GJ63100@giles.gnomon.org.uk> <20150507220848.GK63100@giles.gnomon.org.uk> Date: Thu, 7 May 2015 19:16:12 -0700 Message-ID: From: Adam Back To: Roy Badami Content-Type: multipart/alternative; boundary=001a11405594b7bcfc0515889ca0 X-Provags-ID: V03:K0:V9IbGM7kerb+VmX9llK84wEAnOJkuuTwO7IVXqt0KViYyklh841 FuDqIXhdPW6wps2xgNlZ/v3OjLIhAHamR79VHA7/HDO7rO8NPitZHPe0vRcWyAJEpArOquV POD+5oMfGOsWCy0SnLbHz+BoaCEXb8AxwUt/LqVgyi2Le0SXSZI0RRDTrDgk5lDDA92dsBE 7sUdxsnNV5TuJpy2ZTCBQ== X-UI-Out-Filterresults: notjunk:1; X-Spam-Score: 1.0 (+) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [74.208.4.194 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message X-Headers-End: 1YqY2J-0006nx-2W Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Mechanics of a hard fork X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 May 2015 02:29:12 -0000 --001a11405594b7bcfc0515889ca0 Content-Type: text/plain; charset=UTF-8 Well this is all very extreme circumstances, and you'd have to assume no rational player with an interest in bitcoin would go there, but to play your analysis forward: users are also not powerless at the extreme: they could change the hash function rendering current deployed ASICs useless in reaction for example, and reset difficulty at the same time, or freeze transactions until some minimum hashrate is reached. People would figure out what is the least bad way forward. Adam On May 7, 2015 3:09 PM, "Roy Badami" wrote: > On Thu, May 07, 2015 at 11:49:28PM +0200, Pieter Wuille wrote: > > I would not modify my node if the change introduced a perpetual 100 BTC > > subsidy per block, even if 99% of miners went along with it. > > Surely, in that scenario Bitcoin is dead. If the fork you prefer has > only 1% of the hash power it is trivially vulnerably not just to a 51% > attack but to a 501% attack, not to mention the fact that you'd only > be getting one block every 16 hours. > > > > > A hardfork is safe when 100% of (economically relevant) users upgrade. If > > miners don't upgrade at that point, they just lose money. > > > > This is why a hashrate-triggered hardfork does not make sense. Either you > > believe everyone will upgrade anyway, and the hashrate doesn't matter. Or > > you are not certain, and the fork is risky, independent of what hashrate > > upgrades. > > Beliefs are all very well, but they can be wrong. Of course we should > not go ahead with a fork that we believe to be dangerous, but > requiring a supermajority of miners is surely a wise precaution. I > fail to see any realistic scenario where 99% of miners vote for the > hard fork to go ahead, and the econonomic majority votes to stay on > the blockchain whose hashrate has just dropped two orders of magnitude > - so low that the mean time between blocks is now over 16 hours. > > > > > And the march 2013 fork showed that miners upgrade at a different > schedule > > than the rest of the network. > > On May 7, 2015 5:44 PM, "Roy Badami" wrote: > > > > > > > > > On the other hand, if 99.99% of the miners updated and only 75% of > > > > merchants and 75% of users updated, then that would be a serioud > split of > > > > the network. > > > > > > But is that a plausible scenario? Certainly *if* the concensus rules > > > required a 99% supermajority of miners for the hard fork to go ahead, > > > then there would be absoltely no rational reason for merchants and > > > users to refuse to upgrade, even if they don't support the changes > > > introduces by the hard fork. Their only choice, if the fork succeeds, > > > is between the active chain and the one that is effectively stalled - > > > and, of course, they can make that choice ahead of time. > > > > > > roy > > > > > > > > > > ------------------------------------------------------------------------------ > > > One dashboard for servers and applications across > Physical-Virtual-Cloud > > > Widest out-of-the-box monitoring support with 50+ applications > > > Performance metrics, stats and reports that give you Actionable > Insights > > > Deep dive visibility with transaction tracing using APM Insight. > > > http://ad.doubleclick.net/ddm/clk/290420510;117567292;y > > > _______________________________________________ > > > Bitcoin-development mailing list > > > Bitcoin-development@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > > > > > > ------------------------------------------------------------------------------ > One dashboard for servers and applications across Physical-Virtual-Cloud > Widest out-of-the-box monitoring support with 50+ applications > Performance metrics, stats and reports that give you Actionable Insights > Deep dive visibility with transaction tracing using APM Insight. > http://ad.doubleclick.net/ddm/clk/290420510;117567292;y > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > --001a11405594b7bcfc0515889ca0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Well this is all very extreme circumstances, and you'd h= ave to assume no rational player with an interest in bitcoin would go there= , but to play your analysis forward: users are also not powerless at the ex= treme: they could change the hash function rendering current deployed ASICs= useless in reaction for example, and reset difficulty at the same time, or= freeze transactions until some minimum hashrate is reached.=C2=A0 People w= ould figure out what is the least bad way forward.

Adam

On May 7, 2015 3:09 PM, "Roy Badami" &= lt;roy@gnomon.org.uk> wrote:
On Thu, May 07, 2015 a= t 11:49:28PM +0200, Pieter Wuille wrote:
> I would not modify my node if the change introduced a perpetual 100 BT= C
> subsidy per block, even if 99% of miners went along with it.

Surely, in that scenario Bitcoin is dead.=C2=A0 If the fork you prefer has<= br> only 1% of the hash power it is trivially vulnerably not just to a 51%
attack but to a 501% attack, not to mention the fact that you'd only be getting one block every 16 hours.

>
> A hardfork is safe when 100% of (economically relevant) users upgrade.= If
> miners don't upgrade at that point, they just lose money.
>
> This is why a hashrate-triggered hardfork does not make sense. Either = you
> believe everyone will upgrade anyway, and the hashrate doesn't mat= ter. Or
> you are not certain, and the fork is risky, independent of what hashra= te
> upgrades.

Beliefs are all very well, but they can be wrong.=C2=A0 Of course we should=
not go ahead with a fork that we believe to be dangerous, but
requiring a supermajority of miners is surely a wise precaution.=C2=A0 I fail to see any realistic scenario where 99% of miners vote for the
hard fork to go ahead, and the econonomic majority votes to stay on
the blockchain whose hashrate has just dropped two orders of magnitude
- so low that the mean time between blocks is now over 16 hours.

>
> And the march 2013 fork showed that miners upgrade at a different sche= dule
> than the rest of the network.
> On May 7, 2015 5:44 PM, "Roy Badami" <roy@gnomon.org.uk> wrote:
>
> >
> > > On the other hand, if 99.99% of the miners updated and only = 75% of
> > > merchants and 75% of users updated, then that would be a ser= ioud split of
> > > the network.
> >
> > But is that a plausible scenario?=C2=A0 Certainly *if* the concen= sus rules
> > required a 99% supermajority of miners for the hard fork to go ah= ead,
> > then there would be absoltely no rational reason for merchants an= d
> > users to refuse to upgrade, even if they don't support the ch= anges
> > introduces by the hard fork.=C2=A0 Their only choice, if the fork= succeeds,
> > is between the active chain and the one that is effectively stall= ed -
> > and, of course, they can make that choice ahead of time.
> >
> > roy
> >
> >
> > -----------------------------------------------------------------= -------------
> > One dashboard for servers and applications across Physical-Virtua= l-Cloud
> > Widest out-of-the-box monitoring support with 50+ applications > > Performance metrics, stats and reports that give you Actionable I= nsights
> > Deep dive visibility with transaction tracing using APM Insight.<= br> > > http://ad.doubleclick.net/ddm/clk/290420510;117567292;= y
> > _______________________________________________
> > Bitcoin-development mailing list
> > Bitc= oin-development@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/= bitcoin-development
> >

---------------------------------------------------------------------------= ---
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Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight.
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