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 AB0258D4 for ; Fri, 20 May 2016 08:45:43 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail149095.authsmtp.com (outmail149095.authsmtp.com [62.13.149.95]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id E6967199 for ; Fri, 20 May 2016 08:45:42 +0000 (UTC) Received: from mail-c247.authsmtp.com (mail-c247.authsmtp.com [62.13.128.247]) by punt24.authsmtp.com (8.14.2/8.14.2/) with ESMTP id u4K8jeIU082287; Fri, 20 May 2016 09:45:40 +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 u4K8jbit025393 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 20 May 2016 09:45:38 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 19B62400FA; Fri, 20 May 2016 08:44:09 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id 13AD620576; Fri, 20 May 2016 04:45:35 -0400 (EDT) Date: Fri, 20 May 2016 04:45:35 -0400 From: Peter Todd To: Nick ODell Message-ID: <20160520084535.GA5445@fedora-21-dvm> References: <20160517132311.GA21656@fedora-21-dvm> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="zhXaljGHf11kAtnf" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: 3a06e34a-1e67-11e6-bcde-0015176ca198 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdAIUFVQNAgsB AmAbW11eVFh7Wms7 bghPaBtcak9QXgdq T0pMXVMcUQETCUZT X1oeUBxxfgYIfXx1 bQhhD3BdCUd+JFt8 F0hTCGwHMGF9OjNL BV1YdwJRcQRMLU5E Y1gxNiYHcQ5VPz4z GA41ejw8IwAXDS1W QwcCZW8ucWFDJTMg Dz8YGiozHQUkXT8+ KxE4I1gAVHkQLkV6 FVw+HHYRLxIUARw8 V21ABCZIKlVJexoM RShdWEsfDDhQRztH agAA 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 Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] Making UTXO Set Growth Irrelevant With Low-Latency Delayed TXO Commitments 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: Fri, 20 May 2016 08:45:43 -0000 --zhXaljGHf11kAtnf Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 19, 2016 at 04:23:28PM -0600, Nick ODell wrote: > What if two people create transactions from oupoints within the same MMR > tree tip, at the same time? >=20 > For example, I create transaction A plus an MMR proof that MMR tip X will > become Y. >=20 > On the other side of the planet, someone else creates transaction B, plus > an MMR proof that tip X will become Z. >=20 > Can a miner who receives A and B put both into a block, without access to > the outputs that were pruned? The MMR proofs provided by transactions aren't proofs of *how* the MMR shou= ld be be changd; they're just proofs that the MMR is in a certain state right = now. You're situation is just an example of a double-spend, that miners have to detect if they don't want to create invalid blocks. Specifically, if I understand your example correctly, they'd be rejected by the STXO set. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --zhXaljGHf11kAtnf Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJXPs6sAAoJEGOZARBE6K+yxh0H/2SfXh5CHagAPhgZF2noA/5k jgUuVBqWL7Gh3GqulRSSkvshZS+O7WAWhl7CsKubOkox19B2IKfADZxR2rHHkjYi 2slD/ijwKMZYPvr3JiyfbprF8vTqBj4k+LYfyS9i7pRMqewF/a8pHg80SUAmBfUZ K3rX24Iiiv57UtIAdYZWsV02ez4PQzBTC2jK9Pk5PBX4y58ZZq1jihyrmaUXBG2u 2sd62L5BDg0+/GCk7DGPo74PW6lHizfyj4v77ONdxM1s8IXy0g9C1sUcWx/2c7Np Al634ZIBc4X1EVDZCk+codZ0iHGVYM0neN5sZLbVP9a2gw1i/7re3mqNg152OQw= =DdXP -----END PGP SIGNATURE----- --zhXaljGHf11kAtnf--