Return-Path: Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 8BB71C0032 for ; Thu, 6 Jul 2023 16:23:10 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 59CE54156F for ; Thu, 6 Jul 2023 16:23:10 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 59CE54156F Authentication-Results: smtp2.osuosl.org; dkim=pass (2048-bit key) header.d=protonmail.com header.i=@protonmail.com header.a=rsa-sha256 header.s=protonmail3 header.b=xg+p+mod X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -0.699 X-Spam-Level: X-Spam-Status: No, score=-0.699 tagged_above=-999 required=5 tests=[BAYES_05=-0.5, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id H78i_gB09hXN for ; Thu, 6 Jul 2023 16:23:09 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org E2BC440B34 Received: from mail-4324.protonmail.ch (mail-4324.protonmail.ch [185.70.43.24]) by smtp2.osuosl.org (Postfix) with ESMTPS id E2BC440B34 for ; Thu, 6 Jul 2023 16:23:08 +0000 (UTC) Date: Thu, 06 Jul 2023 16:22:44 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1688660581; x=1688919781; bh=MSFBOE4DLC0YIdmdbiftOAL7Eempz5O26i77RvjSZo0=; h=Date:To:From:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=xg+p+modt2Hdt/xBjxkgOJUbuoko2Dt5oisj9V84yl9oEBtJPzohYEJEd18fqizS1 MdFjjJnpIIuZoaWZrfdCvpDv9Zq+7k74gRvSPjMQclgTqu5Yv7aMd0R4PSzcVnLrX9 6/GxRIRYnzYpSQt37MQGnlH4BjN6/x0XRIFnplTuyh/PYGeZvNiaqghlg5CX5ZkpdP T9P6sgnkcEDBA04S9NocB/6r+B7/QnSapSgYbJNX9oUviE1CQMycufCRsRlc3UxomG ZT236/Ev3+r2ZB/DkGAReGjvipKTwVSZNX1mg0q5Ne+OK+LpCb1uHrzvbLMEvpclIK KeCGRF1XfhiUA== To: Bitcoin Protocol Discussion From: alicexbt Message-ID: Feedback-ID: 40602938:user:proton MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Thu, 06 Jul 2023 16:44:26 +0000 Subject: [bitcoin-dev] Denial of Service using Package Relay 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: Thu, 06 Jul 2023 16:23:10 -0000 Hi Bitcoin Developers, I think its possible to use [package relay][0] for DoS attack in coinjoin. = A few other projects could also be affected by packages. Since its a propos= al that adds new P2P messages, transaction relay etc. its as important as a= ny soft fork. Let me know if I am missing something. Consider there are 2 coinjoin implementations: A and B 1) Register input in A 2) Double spend same input with zero fee to your own address 3) Register unconfirmed UTXO from 2 in B 4) B relays a package in which coinjoin transaction (child) pays for 2 (par= ent) Users and coinjoin implementation B, both are incentivized to attack in thi= s case. Attacker could also use a different approach and register same input in A, = B although there are some tradeoffs: - If input gets included in a coinjoin transaction broadcasted by A, there = is nothing much B can do about it. RBF with multiple users isn't easy and c= ostly. - Implementation with less users participating in a round would have an adv= antage. [0]: https://gist.github.com/sdaftuar/8756699bfcad4d3806ba9f3396d4e66a /dev/fd0 floppy disk guy Sent with Proton Mail secure email.