From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9AEA6C016F for ; Mon, 22 Jun 2020 08:15:45 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 8A04480EC3 for ; Mon, 22 Jun 2020 08:15:45 +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 VklXtItd7YZr for ; Mon, 22 Jun 2020 08:15:42 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-40140.protonmail.ch (mail-40140.protonmail.ch [185.70.40.140]) by fraxinus.osuosl.org (Postfix) with ESMTPS id B7ADC863D9 for ; Mon, 22 Jun 2020 08:15:42 +0000 (UTC) Date: Mon, 22 Jun 2020 08:15:37 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail; t=1592813740; bh=4ufDAYpemMD6ja0EabLfrxZjt1v2Dt/TZGV3g3LDNH0=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=I3ZZmljcBI5EkSPK27RFAsZMbBKYAVKlJhUxq5yrXyjPRvsC/BW+rV8POcelm5Mx7 lftjpFs+3q58M4h2byprd4aHCe6GrDz79H/7H1darADd+MQ8xHO2QA1RT1wJ+d+xrI iJfxCNFM8U3umz6Y7+RUI9tjXHwBlJ+ot6pWHY00= To: Bastien TEINTURIER From: ZmnSCPxj Reply-To: ZmnSCPxj Message-ID: In-Reply-To: References: <67334082-5ABA-45C7-9C09-FF19B119C80D@mattcorallo.com> <62P_3wvv8z7AVCdKPfh-bs30-LliHkx9GI9Og3wqIK6hadIG0d6MJJm077zac1erpPUy31FqgZjkAjEl9AQtrOCg4XA5cxozBb7-OIbbgvE=@protonmail.com> <4c4f3a06-0078-ef6a-7b06-7484f0f9edf1@mattcorallo.com> <20200619195846.fclw4ilngvbbf2kk@ganymede> <20200619205220.fshbr7pbijaerbf2@ganymede> <20200620103647.g62srlcxbjqpaqj6@ganymede> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: Bitcoin Protocol Discussion , lightning-dev Subject: Re: [bitcoin-dev] [Lightning-dev] RBF Pinning with Counterparties and Competing Interest 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: Mon, 22 Jun 2020 08:15:45 -0000 Good morning Bastien, > Thanks for the detailed write-up on how it affects incentives and central= ization, > these are good points. I need to spend more time thinking about them. > > > This is one reason I suggested using independent pay-to-preimage > > transactions[1] > > While this works as a technical solution, I think it has some incentives = issues too. > In this attack, I believe the miners that hide the preimage tx in their m= empool have > to be accomplice with the attacker, otherwise they would share that tx wi= th some of > their peers, and some non-miner nodes would get that preimage tx and be a= ble to > gossip them off-chain (and even relay them to other mempools). I believe this is technically possible with current mempool rules, without = miners cooperating with the attacker. Basically, the attacker releases two transactions with near-equal fees, so = that neither can RBF the other. It releases the preimage tx near miners, and the timelock tx near non-miner= s. Nodes at the boundaries between those that receive the preimage tx and the = timelock tx will receive both. However, they will receive one or the other first. Which one they receive first will be what they keep, and they will reject t= he other (and *not* propagate the other), because the difference in fees is= not enough to get past the RBF rules (which requires not just a feerate in= crease, but also an increase in absolute fee, of at least the minimum relay= feerate times transaction size). Because they reject the other tx, they do not propagate the other tx, so th= e boundary between the two txes is inviolate, neither can get past that bou= ndary, this occurs even if everyone is running 100% unmodified Bitcoin Core= code. I am not a mempool expert and my understanding may be incorrect. Regards, ZmnSCPxj