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 9170798C for ; Thu, 6 Apr 2017 02:31:30 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail149084.authsmtp.net (outmail149084.authsmtp.net [62.13.149.84]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 45D1CF0 for ; Thu, 6 Apr 2017 02:31:28 +0000 (UTC) Received: from mail-c247.authsmtp.com (mail-c247.authsmtp.com [62.13.128.247]) by punt22.authsmtp.com (8.14.2/8.14.2/) with ESMTP id v362VRgB091365; Thu, 6 Apr 2017 03:31:27 +0100 (BST) 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 v362VPL0027020 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 6 Apr 2017 03:31:26 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 98E2D40117; Thu, 6 Apr 2017 02:31:24 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id BEBB0205F6; Wed, 5 Apr 2017 22:31:23 -0400 (EDT) Date: Wed, 5 Apr 2017 22:31:23 -0400 From: Peter Todd To: Gregory Maxwell , Bitcoin Protocol Discussion Message-ID: <20170406023123.GA1071@savin.petertodd.org> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="TB36FDmn/VVEgNH/" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: 2229b712-1a71-11e7-bcdf-0015176ca198 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdgQUGUUGAgsB AmEbW1deU1x7W2U7 bghPaBtcak9QXgdq T0pMXVMcUgZuA3ph eh4eUB5ydQUIfnh5 ZQhgXHJSDkN7d1t8 E0lVCGwHMGB9OjNL Bl1YdwJRcQRMLU5E Y1gxNiYHcQ5VPz4z GA41ejw8IwAXAgVt ChkXKkoVWk8PTHYd QRADFzQzHEsKDyx7 JBs4J0QAVE8NLkw5 MhMmXxoEMxJwQidf A0pKASkRH34+DyQ2 CwhGXEkYeAAA X-Authentic-SMTP: 61633532353630.1038:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 52.5.185.120/25 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 Subject: Re: [bitcoin-dev] BIP proposal: Inhibiting a covert attack on the Bitcoin POW function X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Apr 2017 02:31:30 -0000 --TB36FDmn/VVEgNH/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Apr 05, 2017 at 09:37:45PM +0000, Gregory Maxwell via bitcoin-dev w= rote: > On that basis, I offer the following BIP draft for discussion. > This proposal does not prevent the attack in general, but only > inhibits covert forms of it which are incompatible with > improvements to the Bitcoin protocol. >=20 > I hope that even those of us who would strongly prefer that > ASICBOOST be blocked completely can come together to support > a protective measure that separates concerns by inhibiting > the covert use of it that potentially blocks protocol improvements. While I'm in favour of blocking covert usage of ASICBOOST, there's every re= ason to block non-covert usage of it as well. In a low margin business like mini= ng, the advatange it gives is enormous - quite possibly 10x your profit margin - and given that barrier free access to being able to purchase ASICs is alrea= dy an archilles heal for Bitcoin there is every reason to eliminate this legal vulnerability. Additionally, it's a technical vulnerability as well: we want getting into the ASIC manufacturing and design business to have as low barr= iers to entry as is feasible, and the ASICBOOST exploit significantly increases = the minimum capital requirements to do so. Remember that the whole purpose of PoW is to destroy value on a level playi= ng field. Anything that inhibits a level playing field is an exploit. While th= is isn't standard crypto - we can't fix every exploit completely - since we're going to do a technical change to partially mitigate the ASCIBOOST exploit there is every reason to fully mitigate it. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --TB36FDmn/VVEgNH/ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJY5ah3AAoJECSBQD2l8JH7GA8IAIUs6iRI2hdAKdylxeLQTpuc eORUExcfnk3Prx2OEuxCwe2LoxCCKDJ7SrnQG4cTt+3HJimsti5AcrO1O11XrE/9 owWUahdLsB9/BkYJZKr/b1DZlGVMy3S1xXVDZnbURlrhfhQQ0aQPM5w9oi/1TcHx 0tW4QiSo8OO8CO8wghEheDxdC1pIhrIwCIJxEtmp+xYHwzwFLQgiowBPdgoAFZuJ axKAz4myv7FZ50oZRKbm2omD0b3Y0STxKV4/+Bv1F63bvQtPNOUX4USsz0LLWvS6 1U/cerVD+xk2FEi21ppZEdJNBA5SjJoTpTpHp/Ll5vommMSbT8sepsN4dTRkF/s= =FOmv -----END PGP SIGNATURE----- --TB36FDmn/VVEgNH/--