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 8E711EA4 for ; Wed, 14 Feb 2018 02:07:37 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail2.protonmail.ch (mail2.protonmail.ch [185.70.40.22]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 45D40180 for ; Wed, 14 Feb 2018 02:07:36 +0000 (UTC) Date: Tue, 13 Feb 2018 21:07:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=default; t=1518574052; bh=faPS8AzNOekOiwQ3IaTJrkkL+Xc5wE1DgaE/J7sLMbw=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References: Feedback-ID:From; b=yilWM4N9kzLG7I2xHb1bS7KB3Cv6MRpo6Gz2Kew+mD/44eh0nIQ2xmCafoYunYE0x k0cN+noh4YQawQtap/QMe63rumm01sGGeGlkVIz0iptS1KVn02nMNK16enRCrqLVlL EZ8i2lBcbWt6sEerGb/B/k1+DaQpoB0rqMREKYmI= To: Peter Todd From: rhavar@protonmail.com Reply-To: rhavar@protonmail.com Message-ID: In-Reply-To: <20180213184034.GA10642@fedora-23-dvm> References: <20180212225828.GB8551@fedora-23-dvm> <0uRiPitofHOu2G_7h4lk1q-BKJOZ_x9UecbP8aqyy7FLlrme06od_H79G7rfIs1uk3Vs470_PSlCHjRqsC9ObqhQRyhZ_9JdEzYJzNd-QRM=@protonmail.com> <20180213184034.GA10642@fedora-23-dvm> Feedback-ID: RdfuD--Ffc-FNb_4UIG1XA3s5stj1f6Yt84KENdha_3WoiW3STYpu7X5uGR72LvTfQZpxEhSRHGSlNfV5XM5RA==: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, FREEMAIL_FROM, 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: Wed, 14 Feb 2018 02:35:20 +0000 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Revisiting BIP 125 RBF policy. 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: Wed, 14 Feb 2018 02:07:37 -0000 On February 13, 2018 1:40 PM, Peter Todd wrote: > Yeah, sorry, I just misread what scenario you guys were talking about. II= RC the > term "pinned" may have even been invented by myself, as IIRC I noticed th= e > issue when the RBF patch was being developed years ago. I don't think I h= ad a > solution at the time so I just punted on it. Yeah. I posted that before it was clarified, it's just my message got held = up in the moderation queue so it came out of order at an inconvenient time = >< > I'm not sure that's actually true, as you're only creating transactions s= ets > that are reorg safe. Though I don't have a detailed design in mind so I m= ay be > missing something. It is. T_a and T_ab are "reorg" safe, but if T_a confirms you will still ne= ed to pay Bob in way. But you need to pay him such that in a reorg occurs a= nd suddenly T_ab is mined, you haven't doubled paid him.=20 I've been working on it's implementation, but it's honestly really complex = and hard to test. I outlined the procedure here: https://gist.github.com/RH= avar/cff76a026ece8446c898470db4f35682 which I call "Super Withdrawals". My point though isn't that it's impossible, it's that it's sufficiently com= plex that it's unreasonable to expect anyone to be doing it any time soon. = By relaxing any unnecessary restrictions on bip125, just makes it _drastica= lly_ easier to do certain things. > So here's a question: how many wallets have actually implemented CPFP fee= bumps > for incoming transactions? Never tried it, but I recall seeing it in the electrum gui. I originally tr= ied supporting this myself, but it's kind of annoying. It's generally a bi= t cost-prohibitive to create a transaction specifically for the purpose of = a CPFP fee bump, but since I made transactions pretty frequently (averaged = say every 8 minutes) it doesn't add an additional input for the purpose of = bumping selected incoming transactions. The work flow is reasonably smooth: Alice has sent me 1 BTC with low fees, = I owe Bob some money. I source Alice's output in the payment to Bob, giving= her transaction a fee bump. Both transactions confirm, everyone is happy. However during the whole time I need to watch Alice's transaction because i= f it ever is replaced/conflicted, I need to immediately pay Bob (in a reorg= safe way, so I don't double-pay). It's not terribly hard to do, by making = sure when I pay Bob I use an additional input that I also use for any "repa= yment" but it's enough complexity and hard enough to test that I gave up. The really nice thing of most current send systems (and now especially so w= ith segwit) is everything is pretty much fire and forget. (although I just= schedule in 0.5, 1, 2, 4, .... 32 hours fee bump attempts. But that's just= background that can fail/succeed blindly) > >1. https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2017-July/01468= 8.html > > -- >https://petertodd.org 'peter'[:-1]@petertodd.org > >