Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id A761DBD4 for ; Tue, 26 Jun 2018 05:20:04 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-ua0-f196.google.com (mail-ua0-f196.google.com [209.85.217.196]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 3CBEB12E for ; Tue, 26 Jun 2018 05:20:04 +0000 (UTC) Received: by mail-ua0-f196.google.com with SMTP id u21-v6so828057uao.0 for ; Mon, 25 Jun 2018 22:20:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to; bh=9/9ULTe0Qxeb+DytAJ/QK4uTk/IDnj90RVtF0oIOg/M=; b=c9LGID4l8a5TDP12Oy7TeKUCmDN4gGB+5we75pbLhdoYos7rVntDe5KCHkIeZcUayS 4BC2DCXxHEKy68x37csr8tKfSYSwbIvU7ydd5oLd+5Ytp3LdwF0ZJpo4VagExrauI4SM iq08up/C7IQOKyQYsL52ALYAi/N0jmGF77UJw6TcjsovXSGTXhzXZ3a0mmg86/u+zS/T ONUcGpo6dUbN6x8Shn8I2lAjYRsCqCv+PxglUWnfBbRLkMeKD8e2X4SdavintxhlIFmK Fxy2YMKNpbNZAwNTdZrrMTwoRZI9WEBWZ031sVw9lkYofii5n+2a3kfY3qBaig+8zhsV mi9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to; bh=9/9ULTe0Qxeb+DytAJ/QK4uTk/IDnj90RVtF0oIOg/M=; b=iv2mjUgcZR6TKWG9726+aCCJGOvE3+FMI6MPUpYvYHk2usQBXDZjePRZzHz48CB/xH D9xzmHBW4ajypquo8XUPJVZXH+9yHJKZGB/brjnugIa2D6vys0bWXdZ4sJaSIwruwbry 247wRuGVT6sXjvrg1ZTSZZhqYiNAy8CMt3diDsIpTr+YCpxsv9M/kW0yF3vqxIG5LYPe fF/jMIduERh+OrCxGK99d9TLrr1BSB3A6+tEfDUHIlmcVIuDMM4YW+i2fLzKvr9RLv75 LlpJ3aFhlf/zGlFD87c+ukSMYbt10mkX4fhW3Wwuckgw2JOGv610/bsEaQPWRKIAzkcv sBCQ== X-Gm-Message-State: APt69E0A5WIcM97gf8EqQr3kW3ajZtMasWcO7FGh3x2UNg4hbBohUp8v 0H7e0+kRx7k5/25jMs57Q6ISAcA0LiU8DKEeBcCPQA== X-Google-Smtp-Source: AAOMgpff076B1bwTNzpIX7lpXuBVetwOJ27NvhkTx9Cm1enPVeLUVAhQ6aINXQe8m+bGYGt+d4UMzbOYM5p5rn0EqVY= X-Received: by 2002:a9f:3b06:: with SMTP id i6-v6mr12504uah.75.1529990403182; Mon, 25 Jun 2018 22:20:03 -0700 (PDT) MIME-Version: 1.0 Sender: gmaxwell@gmail.com Received: by 2002:a67:5193:0:0:0:0:0 with HTTP; Mon, 25 Jun 2018 22:20:02 -0700 (PDT) In-Reply-To: References: From: Gregory Maxwell Date: Tue, 26 Jun 2018 05:20:02 +0000 X-Google-Sender-Auth: 4i1AoAOTFRW76zACmLJARTwT3hM Message-ID: To: Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: Re: [bitcoin-dev] BIP proposal - Dandelion: Privacy Preserving Transaction Propagation 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: Tue, 26 Jun 2018 05:20:04 -0000 On Tue, Jun 26, 2018 at 12:12 AM, Bradley Denby via bitcoin-dev wrote: > That's right, the idea is to choose Dandelion relays independently from > whether they support Dandelion. If the chosen nodes do not support > Dandelion, then the transactions are fluffed. Otherwise, the transactions > are relayed along a stem. I don't see any problem with doing that... Although an additional countermeasure we're likely to take against attacks on partial deployment is that we'd likely make the wallet's use of stem forwarding be a configuration option which is initially hidden and set to off. In a subsistent release after dandelion propagation is widely deployed we'd unhide the option and default it to on. This way users don't begin using it until the deployment is relatively dense. I believe this approach is a is sufficient such that it could always select out-peers that were dandelion capable without harm, but at the same time I also don't see a reason that we can't do both. (in fact, for privacy reasons we might want to three-stage the deployment, with the use of dandelion by wallets having a setting of off, sometimes, or always so that attackers can't so easily correlate the use of dandelion with upgrades.)