Return-Path: Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id D0A58C016F for ; Sat, 2 May 2020 14:43:26 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id BE0AA871ED for ; Sat, 2 May 2020 14:43:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mur4xjTSizAq for ; Sat, 2 May 2020 14:43:25 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail-io1-f46.google.com (mail-io1-f46.google.com [209.85.166.46]) by fraxinus.osuosl.org (Postfix) with ESMTPS id D5E19871E4 for ; Sat, 2 May 2020 14:43:25 +0000 (UTC) Received: by mail-io1-f46.google.com with SMTP id 19so7632928ioz.10 for ; Sat, 02 May 2020 07:43:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=blockstream-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZfkYtnBopcJPo5LUTd2Bia4B8fxBTVqsm29g/V9arKk=; b=lQvyn15pF6FDLHveFqKBI0A/vSxlaH9lzq46PRHcYARq/xv8PKQCCww2iiec0GxjTS iIBteQ6FR7qoW4GRRSvz3bTqLiFwxhi4fziNlkFu2pQFMySmuJnY/jf96CWn7HhJfC5+ er/njJfZXMPhNKfZZEtiUAJwmsw9wK2DEdTDJ3z+p/vb9mw11M228M7B2UfXn8ATALh1 Bi24Ln04G6M81qi1VEXPkNpd09obqLJ6L4+SYOoeZtspp14mJjVAENgznxJI76lSTep+ f/thnMdrIh7z7LsNR51uKJnrhxe2d4k5nkzPRmhvUs9Ou8xPWvYkfpEHCG4j8U9JRifq FU8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZfkYtnBopcJPo5LUTd2Bia4B8fxBTVqsm29g/V9arKk=; b=rhgWMQdXGJMn5y5Y615ZpKeNJOGVPxnFG2UTxdjgLdmRqB8+IgVtqzejelFJssntNv wOgUupxiAwNrM0TvaMjtXhxoFH5SDTPXFlC3m2NKWHyn9uOJ0HsUvmqAW4Mx7eHycFKn 0KxrTTwqnoKA/CpIBstJMClb3rHScVeMT4KN0+7yE1QykBH7CVd0bG5/t538iXR20bxG HfDLznrO7gLNaD4ZDuW3If3UOOV0DIIBc6I9MeYB0RMTySjc3VqYTRIRf/qBQ03WCi7W uRmD3QFDrru+WQovqrShhLn0kowaLSLwR/P4GINKl7B66wNkKiAhjxjmkFDKdykHk3qd tEsQ== X-Gm-Message-State: AGi0PuaQa5FiOZIpSbPRN5i88+kVI6gzbyyVzs0iy8a8CtV/XruF73N4 urcgVgSIRSTyWRsrXJb3PEhwM7JsPcqK1mJwp5BWJA== X-Google-Smtp-Source: APiQypIF5Z4OZmJR2p/1TZz4wjelDtLt6rExTqOwKtluQ4G6iczsqiBVknPmhv6muznpop4EgVExef8O/lAqGdXxDlY= X-Received: by 2002:a6b:b512:: with SMTP id e18mr8346896iof.168.1588430605192; Sat, 02 May 2020 07:43:25 -0700 (PDT) MIME-Version: 1.0 References: <20200502142602.rj7q2m32ew6trh6u@erisian.com.au> In-Reply-To: <20200502142602.rj7q2m32ew6trh6u@erisian.com.au> From: "Russell O'Connor" Date: Sat, 2 May 2020 10:43:13 -0400 Message-ID: To: Anthony Towns Content-Type: multipart/alternative; boundary="000000000000f9215005a4ab5186" Cc: jonasd.nick@gmail.com, Bitcoin Protocol Discussion , Pieter Wuille Subject: Re: [bitcoin-dev] BIP-341: Committing to all scriptPubKeys in the signature message 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, 02 May 2020 14:43:26 -0000 --000000000000f9215005a4ab5186 Content-Type: text/plain; charset="UTF-8" > If you didn't verify the output scriptPubKeys, you would *only* be able > to care about fees since you couldn't verify where any of the funds went? > And you'd only be able to say fees are "at least x", since they could be > more if one of the scriptPubKeys turned out to be OP_TRUE eg. That might > almost make sense for a transaction accelerator that's trying to increase > the fees; but only if you were doing it for someone else's transaction > (since otherwise you'd care about the output addresses) and only if you > were happy to not receive any change? Seems like a pretty weird use case? > You are right of course. I was thinking of cases where you only care about where some of the outputs go but not all. But of course, even in that case you will need to wade through all of the output ScriptPubKeys anyways. The current design shares the hashOuputs value with the one computed with BIP-143, and that is a somewhat valuable property to keep. Thanks for setting me straight. --000000000000f9215005a4ab5186 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

If you didn't verify the output scriptPubKeys, you would *only* be able=
to care about fees since you couldn't verify where any of the funds wen= t?
And you'd only be able to say fees are "at least x", since th= ey could be
more if one of the scriptPubKeys turned out to be OP_TRUE eg. That might almost make sense for a transaction accelerator that's trying to increa= se
the fees; but only if you were doing it for someone else's transaction<= br> (since otherwise you'd care about the output addresses) and only if you=
were happy to not receive any change? Seems like a pretty weird use case?

You are right of course.=C2=A0 I was thi= nking of cases where you only care about where some of the outputs go but n= ot all.=C2=A0 But of course, even in that case you will need to wade throug= h all of the output ScriptPubKeys anyways.
The current design sha= res the hashOuputs value with the one computed with BIP-143, and that is a = somewhat valuable property to keep.

Thanks for set= ting me straight.
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