From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TmU5D-0003oh-4P for bitcoin-development@lists.sourceforge.net; Sat, 22 Dec 2012 18:46:03 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.210.169 as permitted sender) client-ip=209.85.210.169; envelope-from=gmaxwell@gmail.com; helo=mail-ia0-f169.google.com; Received: from mail-ia0-f169.google.com ([209.85.210.169]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1TmU57-0006fx-KD for bitcoin-development@lists.sourceforge.net; Sat, 22 Dec 2012 18:46:03 +0000 Received: by mail-ia0-f169.google.com with SMTP id r4so4996795iaj.28 for ; Sat, 22 Dec 2012 10:45:52 -0800 (PST) MIME-Version: 1.0 Received: by 10.50.106.199 with SMTP id gw7mr16167533igb.26.1356201952361; Sat, 22 Dec 2012 10:45:52 -0800 (PST) Received: by 10.64.171.73 with HTTP; Sat, 22 Dec 2012 10:45:52 -0800 (PST) In-Reply-To: References: Date: Sat, 22 Dec 2012 13:45:52 -0500 Message-ID: From: Gregory Maxwell To: Bitcoin Development Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -1.6 (-) 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 (gmaxwell[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 X-Headers-End: 1TmU57-0006fx-KD Subject: [Bitcoin-development] Testnet3 difficulty transition problem? 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: Sat, 22 Dec 2012 18:46:03 -0000 On Sat, Dec 22, 2012 at 1:39 PM, Andreas Schildbach wrote: > Both blocks > > 38304 00000000015bb4069249fa1f41ae61d8a7447aaacc33c50dacd3c3654377fa43 > > and > > 40320 000000008011f56b8c92ff27fb502df5723171c5374673670ef0eee3696aee6d > > are difficulty transition blocks. However, block 40320 has a difficulty > of 1. I know there is this special testnet rule that allows mining a > block at difficulty 1, Yes. > but I always thought you can't use this exception > on difficulty transition blocks. Not so=E2=80=94 but what you're actually seeing is that difficult change is relative to the prior block's difficulty. E.g. if the penultimate block in the difficulty cycle is under the special rule the difficulty change will be relative to 1. (I had intentionally avoided triggering that test case when adding the timewarp attack to the testnet chain in case we had wanted to fix it prior to testnet3's release=E2=80=94 I guess I should have added it sooner = in order to catch the bitcoinj misbehavior!)