From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id A7852DCF for ; Wed, 2 Mar 2016 18:20:48 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail149101.authsmtp.com (outmail149101.authsmtp.com [62.13.149.101]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 1431FEB for ; Wed, 2 Mar 2016 18:20:46 +0000 (UTC) Received: from punt20.authsmtp.com (punt20.authsmtp.com [62.13.128.164]) by punt21.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u22IKjmX074239 for ; Wed, 2 Mar 2016 18:20:45 GMT Received: from mail-c247.authsmtp.com (mail-c247.authsmtp.com [62.13.128.247]) by punt20.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u22IKjeR092697; Wed, 2 Mar 2016 18:20:45 GMT Received: from petertodd.org (ec2-52-5-185-120.compute-1.amazonaws.com [52.5.185.120]) (authenticated bits=0) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u22IKfRs039849 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 2 Mar 2016 18:20:42 GMT Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 985C4401BE; Wed, 2 Mar 2016 18:20:28 +0000 (UTC) Received: by savin (Postfix, from userid 1000) id AB02113FD30; Wed, 2 Mar 2016 13:20:40 -0500 (EST) Received: by savin (hashcash-sendmail, from uid 1000); Wed, 2 Mar 2016 13:20:28 -0500 Date: Wed, 2 Mar 2016 13:20:28 -0500 From: Peter Todd To: Luke Dashjr Message-ID: <20160302182028.GA7783@savin.petertodd.org> References: <201603021456.15820.luke@dashjr.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="+QahgC5+KEYLbs62" Content-Disposition: inline In-Reply-To: <201603021456.15820.luke@dashjr.org> X-Hashcash: 1:28:160302:luke@dashjr.org::snu84zyKFgRcN1fv:06I/C9 X-Hashcash: 1:28:160302:bitcoin-dev@lists.linuxfoundation.org::36vkrDtHVhFYClgw: 0000000000000000000000001NXE X-Server-Quench: 798349bb-e0a3-11e5-bcde-0015176ca198 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdgAUFVQGAgsB AmAbWlxeUl17XWE7 bghPaBtcak9QXgdq T0pMXVMcUQdqeGdX ZF0eURB6cwwIfndx YwhlV3hYWE0oJ1so Qh9XCGwHMGJ9OjNL BV1YdwJRcQRMLU5E Y1gxNiYHcQ5VPz4z GA41ejw8IwAXCC1P Tg8KN1FaXUFDED8s DxwDEzsuFlABWzR7 IwYhMhYVGEkWKEQu MV5J X-Authentic-SMTP: 61633532353630.1038:706 X-AuthFastPath: 0 (Was 255) X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Wed, 02 Mar 2016 18:37:18 +0000 Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] Hardfork to fix difficulty drop algorithm X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Mar 2016 18:20:48 -0000 --+QahgC5+KEYLbs62 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 02, 2016 at 02:56:14PM +0000, Luke Dashjr via bitcoin-dev wrote: > To alleviate this risk, it seems reasonable to propose a hardfork to the= =20 > difficulty adjustment algorithm so it can adapt quicker to such a signifi= cant=20 > drop in mining rate. BtcDrak tells me he has well-tested code for this in= his=20 > altcoin, which has seen some roller-coaster hashrates, so it may even be= =20 > possible to have such a proposal ready in time to be deployed alongside S= egWit=20 > to take effect in time for the upcoming subsidy halving. If this slips, I= =20 > think it may be reasonable to push for at least code-readiness before Jul= y,=20 > and possibly roll it into any other hardfork proposed before or around th= at=20 > time. >=20 > I am unaware of any reason this would be controversial, so if anyone has = a=20 > problem with such a change, please speak up sooner rather than later. Oth= er=20 > ideas or concerns are of course welcome as well. Changing the difficulty adjustment algorithm significantly changes the security of the whole system, as it lets attackers create fake chains with a lot less hashing power. Given as tx fees rise this problem will hopefully be a one-time issue, a simple fixed difficulty adjustment probably makes sense. No need to bring in new algorithms here with controversial new security tradeoffs. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org 0000000000000000045a03e0e551c4e674f301e0a8eeb217a31ad13580446626 --+QahgC5+KEYLbs62 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGrBAEBCACVBQJW1y7mXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAwNjIxOTI1OTRkYTZiYWNjZGJiMjEzZGJjNWQ1MTJmMDgz YTdlMTMzNjVkNmY5OTYvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQJIFAPaXwkfvT8Af+OcgVI3IVXGnQnQ+cN0RXwc+i yry9mPXp4Bqkbt3HOX1tmxRoHZtWxzjRh2HFXIuQM/Zl6LNFYeeSuJC/iBWlWLsI O4FLhgXa9q4vK8nMAv+28rPpDpa7V33uU/Tc7M92zqTTa7tkAXqi/cnrBFA2TzXS syGXd/s/lmKvZI8IX+xkqF76HOKMldtkPWPBxHhrPNRG7yv6yRMzib5OKWHMcxpr O0pIMoO5uQSPnAwcOvz60+7eeik4J5Czx96RIjsbSUYXXG3XRmCVm6F7uclFy9Rp UDwc43YAdJdhwY0B+JDXS+gJ+ytlOe7AJkgxu56pC+sWrryysniaxud/KFcKOA== =3CWU -----END PGP SIGNATURE----- --+QahgC5+KEYLbs62--