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 F342AA151 for ; Fri, 1 Feb 2019 09:36:54 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-40133.protonmail.ch (mail-40133.protonmail.ch [185.70.40.133]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 54307712 for ; Fri, 1 Feb 2019 09:36:54 +0000 (UTC) Date: Fri, 01 Feb 2019 09:36:50 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=default; t=1549013812; bh=3jZThef3Yi8NH7MnBC2SZp7e7b/Q2n19idvOYKNF76k=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References: Feedback-ID:From; b=DWGV5jpp+FtTaacWF2AvdsZrxwjaub3japiqFCwgSHYzsz+Ig0HeK1NhZraABfaTk NAAoayX4oKYBFYb3IHU8yUEIJH/OeNNLRDEaKML3cW6FYPRVeOvAYYO0mT9DGXjWUc VKgOWwMwc2WU3t7YAzwL2Ankb1umMACiW+zfY0lk= To: Anthony Towns From: ZmnSCPxj Reply-To: ZmnSCPxj Message-ID: In-Reply-To: <20190131060405.e7hefirxcars4bpu@erisian.com.au> References: <9F8C0789-48E9-448A-A239-DB4AFB902A00@xbt.hk> <8z5NQkaOUo9z-wdBphQtZrxIf7OCtVQFvK3neMWvcRsngld5XJs-vt7CLuY46ZOp_pX8gEd92pMdkEkp8CUOMH9lUTw5ocWsbDPiaKdSa2I=@protonmail.com> <34B38940-524D-42B9-8A67-6A62DCE04665@xbt.hk> <20190131060405.e7hefirxcars4bpu@erisian.com.au> Feedback-ID: el4j0RWPRERue64lIQeq9Y2FP-mdB86tFqjmrJyEPR9VAtMovPEo9tvgA0CrTsSHJeeyPXqnoAu6DN-R04uJUg==:Ext:ProtonMail MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, FROM_LOCAL_NOVOWEL, 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 X-Mailman-Approved-At: Fri, 01 Feb 2019 14:56:03 +0000 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Safer NOINPUT with output tagging 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, 01 Feb 2019 09:36:55 -0000 Good morning aj, I certainly agree. I hope that PSBT support becomes much, much, much more widespread. Regards, ZmnSCPxj Sent with ProtonMail Secure Email. =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 Thursday, January 31, 2019 2:04 PM, Anthony Towns wr= ote: > On Mon, Dec 24, 2018 at 11:47:38AM +0000, ZmnSCPxj via bitcoin-dev wrote: > > > A boutique protocol would reduce the number of existing onchain wallets= that could be integrated in such UI. > > Seems like PSBT would be a sufficient protocol: > > 0) lightning node generates a PSBT for a new channel, > with no inputs and a single output of the 2-of-2 address > > 1. wallet funds the PSBT but doesn't sign it, adding a change address > if necessary, and could combine with other tx's bustapay style > > 2. lightning determines txid from PSBT, and creates update/settlement > tx's for funding tx so funds can be recovered > > 3. wallet signs and publishes the PSBT > 4. lightning sees tx on chain and channel is open > > That's a bit more convoluted than "(0) lightning generates an address= and > value, and creates NOINPUT update/settlement tx's for that address/va= lue; > (1) wallet funds address to exactly that value; (2) lightning monitor= s > blockchain for payment to that address" of course. > > But it avoids letting users get into the habit of passing NOINPUT > addresses around, or the risk of a user typo'ing the value and losing > money immediately, and it has the benefit that the wallet can tweak t= he > value if (eg) that avoids a change address or enhances privacy (iirc, > c-lightning tweaks payment values for that reason). If the channel's > closed cooperatively, it also avoids ever needing to publish a NOINPU= T > sig (or NOINPUT tagged output). > > Does that seem a fair trade off? > > Cheers, > aj >