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 6008DDDF for ; Sun, 20 Dec 2015 03:47:13 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-io0-f177.google.com (mail-io0-f177.google.com [209.85.223.177]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D03B5EC for ; Sun, 20 Dec 2015 03:47:12 +0000 (UTC) Received: by mail-io0-f177.google.com with SMTP id q126so126251031iof.2 for ; Sat, 19 Dec 2015 19:47:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=yQRwaZcYILEM/6eR+c189DA0S/9KaZL9AOSCl704LW8=; b=CjoqzCtlLB5gNdD46ukvVyzNUsBZqi3PNuY6cUxkkw1a6lrimm+4/rNgWqr7eQhwT3 2Pz8FK1WyLv9/dckshOCbG01UWNcA8QslBG8kaUSpHkaNhQbYy68vUj92V1QcFFsN6g/ ZdvhAbPhnqqfavUb4IqEIbxPv+FHF8w/ZkPQ/iczLI1OKGpBeVASKV0lLtWmaW2JrTs1 Hun2LhCSxKiOtOAQOfrPU5T1baNhrSPVX8b949rMvsk61U6HFDSgTYzpKQqrSWAMnInR y9pXR3Ivl/zMojdKR9mP4IG2PwAdwtYhkc7urEbFVCkm7f1XA4EVB3ud5z+AzSH1nsHG /OxA== MIME-Version: 1.0 X-Received: by 10.107.40.76 with SMTP id o73mr8968114ioo.157.1450583232353; Sat, 19 Dec 2015 19:47:12 -0800 (PST) Sender: nbvfour@gmail.com Received: by 10.36.20.142 with HTTP; Sat, 19 Dec 2015 19:47:12 -0800 (PST) In-Reply-To: <219f125cee6ca68fd27016642e38fdf1@xbt.hk> References: <20151219184240.GB12893@muck> <219f125cee6ca68fd27016642e38fdf1@xbt.hk> Date: Sat, 19 Dec 2015 19:47:12 -0800 X-Google-Sender-Auth: 163BHEeoPb5H4S9-VzbsCupRIYU Message-ID: From: Chris Priest To: jl2012 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, 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 Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] We need to fix the block withholding attack X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 20 Dec 2015 03:47:13 -0000 On 12/19/15, jl2012 wrote: > Chris Priest via bitcoin-dev =E6=96=BC 2015-12-19 22:34 =E5=AF=AB=E5=88= =B0: >> Block witholding attacks are only possible if you have a majority of >> hashpower. If you only have 20% hashpower, you can't do this attack. >> Currently, this attack is only a theoretical attack, as the ones with >> all the hashpower today are not engaging in this behavior. Even if >> someone who had a lot of hashpower decided to pull off this attack, >> they wouldn't be able to disrupt much. Once that time comes, then I >> think this problem should be solved, until then it should be a low >> priority. There are more important things to work on in the meantime. >> > > This is not true. For a pool with 5% total hash rate, an attacker only > needs 0.5% of hash rate to sabotage 10% of their income. It's already > enough to kill the pool > > This begs the question: If this is such a devastating attack, then why hasn't this attack brought down every pool in existence? As far as I'm aware, there are many pools in operation despite this possibility.