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 59ACDE36 for ; Tue, 15 Oct 2019 15:50:35 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-40130.protonmail.ch (mail-40130.protonmail.ch [185.70.40.130]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 686E26D6 for ; Tue, 15 Oct 2019 15:50:33 +0000 (UTC) Date: Tue, 15 Oct 2019 15:50:29 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=default; t=1571154631; bh=UyUoLAoV4c+WjU11bHGnUhj6z6MpP40CzsFCO91FDm8=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References: Feedback-ID:From; b=jxs6MhHgaJt94Hs4ez4YlTVc1NnEt+2pLIajmWgt+YW8GKrWfVWbpt78Atstftyxa TQRksUxm1Z5lj1MbIkMxNvUY6VqSofDadGuVMW1/p9cNOIm6PgKwQmXpZYycExOfhJ fQva2+hhUoYOivDxXnRvcCxZAGnYdexZD97zPj1o= To: Braydon Fuller From: =?UTF-8?Q?Joachim_Str=C3=B6mbergson?= Reply-To: =?UTF-8?Q?Joachim_Str=C3=B6mbergson?= Message-ID: In-Reply-To: <7b0d0bff-d898-10ff-5fdb-c982b82054a1@purse.io> References: <42cd5ffd-63e8-b738-c4ea-13d0699b1268@purse.io> <93649df9-27ab-abaf-00f3-da6c528344cc@purse.io> <7b0d0bff-d898-10ff-5fdb-c982b82054a1@purse.io> Feedback-ID: rtGq1wInl4cYyZOA2iZwaHP-4FBFY67Qt3DcVBMZh8YR1tV-3hijnv7SxpdDwGlNdSPgHEykKLn6PcHDKa0D8A==:Ext:ProtonMail MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, 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 X-Mailman-Approved-At: Tue, 15 Oct 2019 15:54:56 +0000 Cc: Bitcoin Protocol Discussion Subject: Re: [bitcoin-dev] Chain width expansion 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, 15 Oct 2019 15:50:35 -0000 > > > > [...] to generate much longer chain with superslow timestamp increa= se (~5 blocks in 1 second) without increasing difficulty (i.e. staying at m= in. diff.). [...] > > > > In that case, it would take about 7 minutes of block time seconds f= or > > > > the next retarget period, every 2016 blocks, and the difficulty wou= ld > > > > adjust. The difficulty would adjust in that case as if 2 weeks of b= locks > > > > had been mined in 7 minutes. For the difficulty to remain the same = the > > > > time between blocks needs to be 10 minutes. > > > > This calculation does not apply under time warp attack. You can fak= e timestamps of all blocks except for those relevant to the retarget calcul= ation. Those are only the first and the last block in the 2016 block window= . > > This must be in reference to the non-overlapping difficulty calculation > and off-by-one bug? Indeed.