From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1St38s-0007m6-Du for bitcoin-development@lists.sourceforge.net; Sun, 22 Jul 2012 20:52:42 +0000 X-ACL-Warn: Received: from zinan.dashjr.org ([173.242.112.54]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1St38r-0002Er-IV for bitcoin-development@lists.sourceforge.net; Sun, 22 Jul 2012 20:52:42 +0000 Received: from ishibashi.localnet (unknown [97.96.85.141]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id AA54D560538 for ; Sun, 22 Jul 2012 20:52:38 +0000 (UTC) From: "Luke-Jr" To: bitcoin-development@lists.sourceforge.net Date: Sun, 22 Jul 2012 20:52:25 +0000 User-Agent: KMail/1.13.7 (Linux/3.4.4-gentoo-nestfix; KDE/4.8.3; x86_64; ; ) X-PGP-Key-Fingerprint: E463 A93F 5F31 17EE DE6C 7316 BD02 9424 21F4 889F X-PGP-Key-ID: BD02942421F4889F X-PGP-Keyserver: hkp://pgp.mit.edu MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201207222052.28579.luke@dashjr.org> X-Spam-Score: -0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1St38r-0002Er-IV Subject: [Bitcoin-development] Reconsidering block version number use 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: Sun, 22 Jul 2012 20:52:42 -0000 It just occurred to me that the block version number could easily be used as a cheap "extra nonce" right now. Considering that we will probably see lots of ASIC miners running at 1 TH/s per rig before the end of 2012, it might be desirable to save the block version for this purpose. The current block height in coinbase addition currently proposes to use block version 2. However, the protocol change is in fact to the coinbase transaction, not the block itself (which really doesn't have any extensibility without a hardfork anyway). Perhaps we should consider bumping the coinbase transaction version number to 2 for this instead? Also, Jeff noticed that block 190192 has version==2 without a valid block height in the coinbase. I suspect this may be the result of combining the current blockheight-in-coinbase pullreq with P2Pool. This means that if we go forward with the version==2 marker, we will forever need to make an exception for that block. Moving the version==2 to the coinbase transaction version also means whoever makes that transaction (thus deciding whether to put the height in it or not) also sets the version number - instead of the block version coming from bitcoind and the coinbase transaction coming from P2Pool or other software. Thoughts? Luke