Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WHxzs-0001Rt-3m for bitcoin-development@lists.sourceforge.net; Mon, 24 Feb 2014 16:03:12 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of bitpay.com designates 74.125.82.50 as permitted sender) client-ip=74.125.82.50; envelope-from=jgarzik@bitpay.com; helo=mail-wg0-f50.google.com; Received: from mail-wg0-f50.google.com ([74.125.82.50]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WHxzr-0003Je-0N for bitcoin-development@lists.sourceforge.net; Mon, 24 Feb 2014 16:03:12 +0000 Received: by mail-wg0-f50.google.com with SMTP id z12so4871825wgg.5 for ; Mon, 24 Feb 2014 08:03:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:date:message-id:subject:from:to :content-type; bh=h4HDKdG6sHrQtxYs8b/AGLkA9af4xhnuT8dmQyJoxk4=; b=MWcSZr+us3uwCrcLg61bDmAtkf/Enyp1XcBQujIuB/+B5ljYzZFiralZz4lKQrrdVc qwZ5oNY8vjxYyf/sYhp7s6nydFP0MOM0trixqxHbFbd4EWKFHpUjJmhmzSpvJc38MHVL VH08NTt64aHgPplBkfuewLxDx2plQbQx3p1K97RW3nrssyL8V71dXl9opbH984wR/Ni9 PDFBMi5HGA8WT09vYr95Rmsgofat7UeKouQIiwaFSNFGohCHSkBfHXqkbsH1G0LDJzBJ Nx1AvtwzZyU6DA8fw3fpEmpRljI0adAjc1iLYh62KmnfL4sAEKa4tXd0azcF3B9MRA5l nolQ== X-Gm-Message-State: ALoCoQkg6UGm+X2s1eXtsw8ka7Dw7tqTS6l4ure2TrBb5LgmAUDV8o7E2rzvvMECADrcurlnMejS MIME-Version: 1.0 X-Received: by 10.180.149.143 with SMTP id ua15mr14676373wib.36.1393257784726; Mon, 24 Feb 2014 08:03:04 -0800 (PST) Received: by 10.194.82.197 with HTTP; Mon, 24 Feb 2014 08:03:04 -0800 (PST) Date: Mon, 24 Feb 2014 11:03:04 -0500 Message-ID: From: Jeff Garzik To: Bitcoin Dev Content-Type: text/plain; charset=ISO-8859-1 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 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: 1WHxzr-0003Je-0N Subject: [Bitcoin-development] On OP_RETURN in upcoming 0.9 release 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: Mon, 24 Feb 2014 16:03:12 -0000 An update in forthcoming 0.9 release includes a change to make OP_RETURN standard, permitted a small amount of metadata to be attached to a transaction: https://github.com/bitcoin/bitcoin/pull/2738 There was always going to be some level of controversy attached to this. However, some issues, perceptions and questions are bubbling up, and it seemed fair to cover them on the list, not just IRC. 1) FAQ: Why 80 bytes of data? This is the leading programmer question, and it was not really documented well at all. Simple answer: 2x SHA256 or 1x SHA512, plus some tiny bit of metadata. Some schemes are of the nature "BOND" rather than just plain hash. A common IRC proposal seems to lean towards reducing that from 80. I'll leave it to the crowd to argue about size from there. I do think regular transactions should have the ability to include some metadata. 2) Endorsement of chain data storage. Listening to bitcoin conference corridor discussions, reading forum posts and the occasional article have over-simplified the situation to "core devs endorse data storage over blockchain! let me start uploading my naughty movie collection! IM over blockchain, woo hoo!" Nothing could be further from the truth. It's a way to make data /less damaging/, not an endorsement of data storage in chain as a good idea. MasterCoin and other projects were doing -even worse- things, such as storing data in forever-unspendable TX outputs, bloating the UTXO for eternity. It seems reasonable to have a release note to this effect in the 0.9 release announcement, IMO. -- Jeff Garzik Bitcoin core developer and open source evangelist BitPay, Inc. https://bitpay.com/