Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 6D14F8F5 for ; Sun, 22 May 2016 08:55:39 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail149082.authsmtp.co.uk (outmail149082.authsmtp.co.uk [62.13.149.82]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id B592E174 for ; Sun, 22 May 2016 08:55:38 +0000 (UTC) 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 u4M8ta2j005740; Sun, 22 May 2016 09:55:36 +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 u4M8tYbB040336 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 22 May 2016 09:55:35 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 16FBA400F9; Sun, 22 May 2016 08:54:05 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id 9F3C320579; Sun, 22 May 2016 04:55:33 -0400 (EDT) Date: Sun, 22 May 2016 04:55:33 -0400 From: Peter Todd To: Johnson Lau Message-ID: <20160522085533.GA10746@fedora-21-dvm> References: <20160517132311.GA21656@fedora-21-dvm> <68A4772D-D423-45F9-ADB7-95BEB3E66F43@xbt.hk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="2oS5YaxWCcQjTEyO" Content-Disposition: inline In-Reply-To: <68A4772D-D423-45F9-ADB7-95BEB3E66F43@xbt.hk> User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: f31206ef-1ffa-11e6-bcde-0015176ca198 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aAdMdAAUFVQNAgsB AmAbW11eVVh7WmU7 bghPaBtcak9QXgdq T0pMXVMcUQEVCVho VGweVhlxdAMIfXl0 Ywg0XXFZXEIvI1t8 FBgFCGwHMGF9OjNL 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 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: Sun, 22 May 2016 08:55:39 -0000 --2oS5YaxWCcQjTEyO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, May 20, 2016 at 11:46:32AM +0200, Johnson Lau wrote: > How is this compared to my earlier proposal: https://lists.linuxfoundatio= n.org/pipermail/bitcoin-dev/2015-December/011952.html ? >=20 > In my proposal, only the (pruned) UTXO set, and 32 bytes per archived blo= ck, are required for mining. But it is probably more difficult for people t= o spend an archived output. They need to know the status of other archived = outputs from the same block. A full re-scan of the blockchain may be needed= to generate the proof but this could be done by a third party archival nod= e. We're working along the same lines, but my proposal is much better fleshed = out; I think you'll find you missed a few details if you flesh out yours in more detail. For instance, since your dormant UTXO list is indexed by UTXO expiration order, it's not possible to do any kind of verification that the contents of that commitment are correct without the global state of all UTXO data - you have no ability to locally verify as nothing commits to the cont= ents of the UTXO set. --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --2oS5YaxWCcQjTEyO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJXQXQDAAoJEGOZARBE6K+y4/AH/3PwJINWeyMk36AsKlxNLgXK 2AiTh5EjYxgOicgpGi30fyR/TbzWltcOKwaVAxlPMiexmzuYV6smJ7yHyxdkW/Q5 pF3T5itshF1X87XMMF8sLvrBCu64uu0mYDwY9L75QU/SwXMwF7tv+YhCxzPtqIww tsl5rjY3pFmw6uQudw1KgihbK7jD2zO6/UhBs72sYKvzEhBk6NxU1Ab8Hk0ua1Xt IOI+CcvlPhhzyfkaSM8B1LjW+L1e6i3ZY4RRkNqriWkQaE/HKNqkHLK8sKTJpILH L/lwq+uG9F+NHAbR3ZdX03f0+M3X8jSur4ZlwwU2ADvN7sE2J8mvVn1PF0TELfY= =EkEa -----END PGP SIGNATURE----- --2oS5YaxWCcQjTEyO--