Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1RTBM2-0004VU-TA for bitcoin-development@lists.sourceforge.net; Wed, 23 Nov 2011 11:51:06 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.161.175 as permitted sender) client-ip=209.85.161.175; envelope-from=timon.elviejo@gmail.com; helo=mail-gx0-f175.google.com; Received: from mail-gx0-f175.google.com ([209.85.161.175]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1RTBM2-0004DR-Az for bitcoin-development@lists.sourceforge.net; Wed, 23 Nov 2011 11:51:06 +0000 Received: by ggnh4 with SMTP id h4so1697651ggn.34 for ; Wed, 23 Nov 2011 03:51:01 -0800 (PST) MIME-Version: 1.0 Received: by 10.204.156.208 with SMTP id y16mr23849161bkw.72.1322049060349; Wed, 23 Nov 2011 03:51:00 -0800 (PST) Received: by 10.223.132.194 with HTTP; Wed, 23 Nov 2011 03:51:00 -0800 (PST) In-Reply-To: <201111231130.58785.andyparkins@gmail.com> References: <201111231035.48690.andyparkins@gmail.com> <201111231130.58785.andyparkins@gmail.com> Date: Wed, 23 Nov 2011 12:51:00 +0100 Message-ID: From: =?ISO-8859-1?Q?Jorge_Tim=F3n?= To: Andy Parkins Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -0.4 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (timon.elviejo[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 2.5 FREEMAIL_REPLY From and body contain different freemails -1.2 AWL AWL: From: address is in the auto white-list X-Headers-End: 1RTBM2-0004DR-Az Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Addressing rapid changes in mining power X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Nov 2011 11:51:07 -0000 With the current system, the timestamp can also be cheated, but miners have no direct incentive to do it. With your system, they increase their probability of mining a block by putting a false timestamp. Also, where's the network clock you're talking about? Isn't it the timestamps in the blockchain? 2011/11/23, Andy Parkins : > On 2011 November 23 Wednesday, Jorge Tim=F3n wrote: >> 2011/11/23, Andy Parkins : >> > Let's abandon the idea of a target difficulty. Instead, every node ju= st >> > >> > generates the most difficulty block it can. Simultaneously, every no= de >> > is listening for "the most difficult block generated before time T"; >> > with T being >> > picked to be the block generation rate (10 minutes). >> >> A miner could try to obtain more difficulty out of time and cheat its >> reported datetime (T). > > Just as with the current system. > > The defence is that on receipt of a block, its timestamp is checked again= st > the node's own clock and averaged network clock. Blocks out of that band > are > rejected. > > > Andy > -- > Dr Andy Parkins > andyparkins@gmail.com > --=20 Jorge Tim=F3n