From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id A1E5CC0012 for ; Sat, 11 Dec 2021 16:21:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 7B14961B3A for ; Sat, 11 Dec 2021 16:21:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.102 X-Spam-Level: X-Spam-Status: No, score=-2.102 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: smtp3.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=wuille.net Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Zf03sythD-Rv for ; Sat, 11 Dec 2021 16:21:37 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from mail-4321.protonmail.ch (mail-4321.protonmail.ch [185.70.43.21]) by smtp3.osuosl.org (Postfix) with ESMTPS id EF8A461B39 for ; Sat, 11 Dec 2021 16:21:36 +0000 (UTC) Received: from mail-0201.mail-europe.com (mail-0201.mail-europe.com [51.77.79.158]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by mail-4321.protonmail.ch (Postfix) with ESMTPS id 4JBChG4GTdz4wy9b for ; Sat, 11 Dec 2021 16:21:33 +0000 (UTC) Authentication-Results: mail-4321.protonmail.ch; dkim=pass (2048-bit key) header.d=wuille.net header.i=@wuille.net header.b="OOsQxhza" Date: Sat, 11 Dec 2021 16:21:21 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wuille.net; s=protonmail; t=1639239684; bh=zkNH37sAc/yxz6CuhTjAEqU0kPdgG5deuFHVKSjrhZI=; h=Date:To:From:Reply-To:Subject:Message-ID:In-Reply-To:References: From:To:Cc; b=OOsQxhzaTT31APuiQB6YndDu1+XLgr1xhVGb6+aSlTeQ1S82i4kvhUUIMI2AzsSzS ytsgvryYoFvwqI8ikNOCwgVtm8R6/ZED8xnAgMc5jJOAOuBvHIN2cZCClCoJmm1gt4 artXSZiVbQNnWal3unl1KUM8poDdkAK4U+pZ6oD+ZdscXsFJa3+d8LwtKyMR49dc78 6y5LcEywWD1CF8+hbwxIzSa4V6Tb1gvaPfSvJQMtOcspONavkAr//TI9ECnQ7FXDDJ AjpnCt2okSq9b4EyGOskcLrW6Za56x1vfj1zSEr4JqrWgGviKCVjfM5ty2EZV+ywsf lggYDqEGbUO4w== To: Bitcoin Protocol Discussion From: Pieter Wuille Reply-To: Pieter Wuille Message-ID: In-Reply-To: <1fbf0ef8b1b42979361b5df0b09c2dcd@willtech.com.au> References: <1fbf0ef8b1b42979361b5df0b09c2dcd@willtech.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Sat, 11 Dec 2021 17:20:15 +0000 Subject: Re: [bitcoin-dev] Rebroadcast mechanism in Bitcoin P2P network 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, 11 Dec 2021 16:21:38 -0000 > It is that the solution to privacy is to use privacy-enhancing network > communications, such as TOR. I am not against a mechanism to rebroadcast > transactions more robustly if the mempool of adjoining nodes has > forgotten about them, but the truth is, all transactions originate from > some node, and there are methods that allow an individual node to be > identified as the likely source of a transaction unless privacy-enabled > networks are utilised. Having a different method to cause rebroadcast > does not obfuscate the origin. You're talking about distinct aspects of transaction privacy. The rebroadcasting approach as it exists on the network, where wallets are = responsible for their own rebroadcasting, directly reveals to your peers a = relation between nodes and transactions: whenever any node relays the same = transaction twice, it almost certainly implies they are the origin. This is just a node-transaction relation, and not necessarily IP-transactio= n relation. The latter can indeed be avoided by only connecting over Tor, o= r using other privacy networks, but just hiding the relation with IP addres= ses isn't sufficient (and has its own downsides; e.g. Tor-only connectivity= is far more susceptible to partition/Eclipse/DoS attacks). For example see= ing the same node (even without knowing its IP) rebroadcast two transaction= lets an observe infer a relation between those transactions, and that too = is a privacy leak. I believe moving to a model where mempools/nodes themselves are responsible= for rebroadcasting is a great solution to improving this specific problem,= simply because if everyone rebroadcasts, the original author doing it too = does not stand out anymore. It isn't "fixing privacy", it's fixing a specif= ic leak, one of many, but this isn't a black and white property. Cheers, -- Pieter