From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id C491EC0012 for ; Sat, 19 Mar 2022 18:32:10 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 9C7E640904 for ; Sat, 19 Mar 2022 18:32:10 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: 0.603 X-Spam-Level: X-Spam-Status: No, score=0.603 tagged_above=-999 required=5 tests=[BAYES_50=0.8, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: smtp4.osuosl.org (amavisd-new); dkim=pass (1024-bit key) header.d=gazeta.pl Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lfZxgaA5f_Xn for ; Sat, 19 Mar 2022 18:32:08 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from smtpo106.poczta.onet.pl (smtpo106.poczta.onet.pl [213.180.149.159]) by smtp4.osuosl.org (Postfix) with ESMTPS id 42DE540902 for ; Sat, 19 Mar 2022 18:32:07 +0000 (UTC) Received: from pmq4v.m5r2.onet (pmq4v.m5r2.onet [10.174.32.70]) by smtp.poczta.onet.pl (Onet) with ESMTP id 4KLTxX2CXzz2K214d; Sat, 19 Mar 2022 19:32:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gazeta.pl; s=2013; t=1647714720; bh=dWJQ9vO+/slZj09iGq1Qwer/v2fitaMFgc1zcnUdlDk=; h=From:To:In-Reply-To:Date:Subject:From; b=oJhZ1KEUB5hc3rwiqKOpXX6ZjGKQGGMoRyrex1x8MDeSl9SKY/2+hWmN5J3eo7LB7 jHSDQeoDr8Cb4YDC3ZA3gL8/rVxEryQteeFd3eKFSgZYZhvX0QX6Mq69nTFhIVcFSo 1V89sYn+AHIGiE5FzzfrNwi02cxdlJ/roILITWGo= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received: from [5.173.240.11] by pmq4v.m5r2.onet via HTTP id ; Sat, 19 Mar 2022 19:32:00 +0100 From: vjudeu@gazeta.pl X-Priority: 3 To: Peter Todd , Bitcoin Protocol Discussion In-Reply-To: Date: Sat, 19 Mar 2022 19:32:00 +0100 Message-Id: <159484190-6f2488890cf1a295d9a781253860f18d@pmq4v.m5r2.onet> X-Mailer: onet.poczta X-Onet-PMQ: ;5.173.240.11;PL;2 X-Mailman-Approved-At: Sat, 19 Mar 2022 19:25:47 +0000 Subject: Re: [bitcoin-dev] OP_RETURN inside TapScript X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Mar 2022 18:32:10 -0000 > There are two use-cases for OP_RETURN: committing to data, and publishing= data. Your proposal can only do the former, not the latter, and there are = use-cases for both. Only the former is needed. Pushing data on-chain is expensive and that kind= of data is useful only to the transaction maker. Also, the latter can be p= ushed on a separate chain (or even a separate layer that is not a chain at = all). Also note that since Taproot we have the latter: we can spend by TapScript = and reveal some public key and tapbranches. It is possible to push more tha= n 80 bytes in this way, so why direct OP_RETURN is needed, except for backw= ard-compatibility? (for example in Segwit commitments) There is only one problem with spending by TapScript, when it comes to publ= ishing data: only the first item is the public key. If we could use public = keys instead of tapbranch hashes, we could literally replace "OP_RETURN " with " ... ". Then, we could u= se unspendable public keys to push data, so OP_RETURN would be obsolete. By the way, committing to data has a lot of use cases, for example the whol= e idea of NameCoin could be implemented on such OP_RETURN's. Instead of cre= ating some special transaction upfront, people could place some hidden comm= itment and reveal that later. Then, there would be no need to produce any n= ew coins out of thin air, because everything would be merge-mined by defaul= t, providing Bitcoin-level Proof of Work protection all the time, 24/7/365.= Then, people could store that revealed commitments on their own chain, jus= t to keep track of who owns which name. And then, that network could easily= turn on and off all Bitcoin features as they please. Lightning Network on = NameCoin? No problem, even the same satoshis could be used to pay for domai= ns! On 2022-03-16 19:21:37 user Peter Todd wrote: > On Thu, Feb 24, 2022 at 10:02:08AM +0100, vjudeu via bitcoin-dev wrote: > Since Taproot was activated, we no longer need separate OP_RETURN outputs= to be pushed on-chain. If we want to attach any data to a transaction, we = can create "OP_RETURN " as a branch in the TapScript. In this way= , we can store that data off-chain and we can always prove that they are co= nnected with some taproot address, that was pushed on-chain. Also, we can s= tore more than 80 bytes for "free", because no such taproot branch will be = ever pushed on-chain and used as an input. That means we can use "OP_RETURN= <1.5 GB of data>", create some address having that taproot branch, and lat= er prove to anyone that such "1.5 GB of data" is connected with our taproot= address. There are two use-cases for OP_RETURN: committing to data, and publishing d= ata. Your proposal can only do the former, not the latter, and there are use-cas= es for both. -- = https://petertodd.org 'peter'[:-1]@petertodd.org