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 CD15341C for ; Sat, 25 Mar 2017 16:13:05 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from forward1.bravehost.com (forward1.bravehost.com [65.39.211.65]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 251CD147 for ; Sat, 25 Mar 2017 16:13:05 +0000 (UTC) X-Virus-Scanned: amavisd-new at bravehost.com Received: from [10.137.4.20] (unknown [109.236.90.209]) (Authenticated sender: cannon@cannon-ciota.info) by forward1.bravehost.com (Postfix) with ESMTPSA id 0D6FE311C; Sat, 25 Mar 2017 09:12:59 -0700 (PDT) To: Aymeric Vitte , Bitcoin Protocol Discussion References: <5b9ba6c4-6d8f-9c0b-2420-2be6c30f87b5@cannon-ciota.info> <35ba77db-f95a-4517-c960-8ad42a633ba0@gmail.com> From: CANNON Message-ID: Date: Sat, 25 Mar 2017 16:12:54 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.6.0 MIME-Version: 1.0 In-Reply-To: <35ba77db-f95a-4517-c960-8ad42a633ba0@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,LOTS_OF_MONEY, RCVD_IN_DNSWL_LOW,T_MONEY_PERCENT autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Sat, 25 Mar 2017 17:44:34 +0000 Subject: Re: [bitcoin-dev] Defending against empty or near empty blocks from malicious miner takeover? 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: Sat, 25 Mar 2017 16:13:06 -0000 On 03/24/2017 07:00 PM, Aymeric Vitte wrote: > I don't know what "Time is running short I fear" stands for and when 50% > is supposed to be reached -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 03/24/2017 07:00 PM, Aymeric Vitte wrote: > I don't know what "Time is running short I fear" stands for and when 50% > is supposed to be reached According to current hashrate distribution tracking site coin.dance, very likely within less than four weeks according to current hashrate takeover rate. While a fork is very likely, that I dont really fear because worst case scenario is that bitcoin still survives and the invalid chain becomes an alt. My fear is the centralized mining power being used to attack the valid chain with intentions on killing it. [1] Shouldn't this 50% attack they are threatening be a concern? If it is a concern, what options are on the table. If it is not a concern please enlightent me as to why. [1] Source: https://www.reddit.com/r/Bitcoin/comments/6172s3/peter_rizun_tells_miners_to_force_a_hard_fork_by/ Text: The attack quoted from his article: https://medium.com/@peter_r/on-the-emerging-consensus-regarding-bitcoins-block-size-limit-insights-from-my-visit-with-2348878a16d8 [Level 2] Anti-split protection  Miners will orphan the blocks of non-compliant miners prior to the first larger block to serve as a reminder to upgrade. Simply due to the possibility of having blocks orphaned, all miners would be motivated to begin signalling for larger blocks once support definitively passes 51%. If some miners hold out (e.g., they may not be paying attention regarding the upgrade), then they will begin to pay attention after losing approximately $15,000 of revenue due to an orphaned block. [Level 3] Anti-split protection  In the scenario where Levels 1 and 2 protection fails to entice all non-compliant miners to upgrade, a small-block minority chain may emerge. To address the risk of coins being spent on this chain (replay risk), majority miners will deploy hash power as needed to ensure the minority chain includes only empty blocks after the forking point. This can easily be accomplished if the majority miners maintain a secret chain of empty blocks  built off their last empty block  publishing only as much of this chain as necessary to orphan any non-empty blocks produced on the minority chain. - -- Cannon PGP Fingerprint: 2BB5 15CD 66E7 4E28 45DC 6494 A5A2 2879 3F06 E832 Email: cannon@cannon-ciota.info NOTICE: ALL EMAIL CORRESPONDENCE NOT SIGNED/ENCRYPTED WITH PGP SHOULD BE CONSIDERED POTENTIALLY FORGED, AND NOT PRIVATE. 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