Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 5F697A48 for ; Fri, 24 Feb 2017 03:15:37 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail148100.authsmtp.co.uk (outmail148100.authsmtp.co.uk [62.13.148.100]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 5E79CA4 for ; Fri, 24 Feb 2017 03:15:36 +0000 (UTC) Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232]) by punt24.authsmtp.com (8.14.2/8.14.2/) with ESMTP id v1O3FYom089106; Fri, 24 Feb 2017 03:15:34 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 v1O3FWTH036134 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 24 Feb 2017 03:15:33 GMT Received: from [127.0.0.1] (localhost [127.0.0.1]) by petertodd.org (Postfix) with ESMTPSA id 044F840576; Fri, 24 Feb 2017 03:15:32 +0000 (UTC) Received: by localhost (Postfix, from userid 1000) id 43C60204AB; Thu, 23 Feb 2017 22:15:31 -0500 (EST) Date: Thu, 23 Feb 2017 22:15:31 -0500 From: Peter Todd To: Bram Cohen Message-ID: <20170224031531.GA32118@savin.petertodd.org> References: <20170223011506.GC905@savin.petertodd.org> <20170223235105.GA28497@savin.petertodd.org> <20170224010943.GA29218@savin.petertodd.org> <20170224025811.GA31911@savin.petertodd.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="82I3+IH0IqGh5yIs" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-Server-Quench: 80fbd698-fa3f-11e6-829f-00151795d556 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR aQdMdAYUHlAWAgsB AmEbW1deUVh7WmA7 bghPaBtcak9QXgdq T0pMXVMcUgQXAmpm YmYeUR9zdAEIcXhz bAhqXiYJCEJzfVsr E00CCGwHMGF9YGIW Bl1YdwJRcQRDe0tA b1YxNiYHcQ5VPz4z GA41ejw8IwAXAWx/ Tx0RIEhaZGMxVhIx SREEHCkuGktt X-Authentic-SMTP: 61633532353630.1037:706 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 Protocol Discussion Subject: Re: [bitcoin-dev] A Better MMR Definition 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, 24 Feb 2017 03:15:37 -0000 --82I3+IH0IqGh5yIs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Feb 23, 2017 at 07:02:36PM -0800, Bram Cohen wrote: > On Thu, Feb 23, 2017 at 6:58 PM, Peter Todd wrote: >=20 > > > > So to be clear, do you agree or disagree with me that you *can* extract= a > > compact proof from a MMR that a given output is unspent? > > >=20 > After wading through your logic on how updates are done, I agree that that > can be done, but apples to apples compact proofs can also be done in a ut= xo > commitment, and proofs of the validity of updates can be done in a utxo > commitment, so there isn't any performance advantage to all that extra > complexity. Glad we're on the same page with regard to what's possible in TXO commitmen= ts. Secondly, am I correct in saying your UTXO commitments scheme requires rand= om access? While you describe it as a "merkle set", obviously to be merkelized it'll have to have an ordering of some kind. What do you propose that order= ing to be? Maybe more specifically, what exact values do you propose to be in the set? --=20 https://petertodd.org 'peter'[:-1]@petertodd.org --82I3+IH0IqGh5yIs Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJYr6VPAAoJECSBQD2l8JH73+8IAKdiAsKTI+BFkaosM/lvSoNP XmqlWOVZVvWvR3iE1yQ4YfN0zM0BU+GPaRfwEevr9y+/IzMFAWHi/m9T+kzykpOE JLgxfB0MXJjBfrSTSgayfF/ZPtILXn4rs/NQlmxp1DxfFce7hucF8x+n/PyjFLjE 776JSYQxOw3GRjcKQaq3J7HYX9oP+9ac3hRjl0SD8ka7XX01x68tqw1ya8fSA0tp qN5e0/yWr3jKJ8SZyX9eX3Ns04xXTefvCmMt3ES4w5q5zwkoQiGP9Q/6FxyffWgN SaQ+ey9iuV2FC7ACPtxFvO3pCyiBp9DD2SJ3Hdn09da3FbjmPZMqb02DCCRjKTQ= =Bm1b -----END PGP SIGNATURE----- --82I3+IH0IqGh5yIs--