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 80FD1D2A for ; Mon, 13 Aug 2018 20:32:40 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail-40132.protonmail.ch (mail-40132.protonmail.ch [185.70.40.132]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 0F6AB165 for ; Mon, 13 Aug 2018 20:32:39 +0000 (UTC) Date: Mon, 13 Aug 2018 20:32:33 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=achow101.com; s=protonmail; t=1534192357; bh=jdQgVNtF1vdEh7O/CaY1QvSAe9gP1CvWE3LoQMmJMTI=; h=Date:To:From:Reply-To:Subject:In-Reply-To:References:Feedback-ID: From; b=E5yULMvbj7sCZSE9ORUzJD0l+9AAwWGsbhfyJ4TViWdTDwB4LIH9OOq2uc8wTTOZu rbDY8Mvc8GHCMhhHb7l3xvm4XleWLLYTtfB+HxD+aYdU+5S08ISufva9sSQxHZ5LwB dRfGTSA39yEbDzhvp8t0GjeA4yxumm2s4cvayt6M= To: Pieter Wuille , Bitcoin Protocol Discussion From: Achow101 Reply-To: Achow101 Message-ID: <7A_00K2wcfdgZMimY9aZ4gUFWyVIPOVrnueAFAosM-S-gIIoHXez6v5GcC8OrfTULz0NZ6n1g3T9jfVbgBvU_jKbgmNd-zlVqQVOC00NphA=@achow101.com> In-Reply-To: References: Feedback-ID: VjS95yl5HLFwBfNLRqi61OdL1ERZPmvMbZRH2ZcBR7SKVUVYPgv7VJsV9uoyC4vIfjYnW8hPXGuLTycZbh49Zw==:Ext:ProtonMail MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, 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] Witness serialization in PSBT non-witness UTXOs 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: Mon, 13 Aug 2018 20:32:40 -0000 Hi, Since the BIP is already in proposed status, I think that we should specify= the non-witness utxo to just be "witness or non-witness" serialization. Th= is maintains compatibility with things that have already implemented but al= so maintains the forwards compatibility that is needed. Andrew =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 Original Me= ssage =E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90=E2=80=90 On August 13, 2018 11:56 AM, Pieter Wuille via bitcoin-dev wrote: > Hello all, > > BIP174 currently specifies that non-witness UTXOs (the transactions > being spent by non-witness inputs) should be serialized in network > format. > > I believe there are two issues with this. > > 1. Even in case the transaction whose output being spent itself has a > witness, this witness is immaterial to PSBT. It's only there to be > able to verify the txid commits to the output/amount being spent, > which can be done without witness. > > 2. "Network format" is a bit ambiguous. We can imagine a future > softfork that introduces a new type of witness. Network format could > be interpreted as including that new witness type, which is clearly > unnecessary (by the above argument), and would gratuitously break > compatibility with existing signers if implemented pedantically. > > So my suggestion is to update the specification to state that > non-witness UTXOs must be serialized without witness. If it's too lat= e > for that, it should instead be updated to explicitly specify with or > witnout witness, but it's safe to drop the witness. > > Opinions? > > Cheers, > > -- > Pieter > > > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev