Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from <jeremy@taplink.co>) id 1WI3l3-0006jG-0f for bitcoin-development@lists.sourceforge.net; Mon, 24 Feb 2014 22:12:17 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of taplink.co designates 50.117.27.232 as permitted sender) client-ip=50.117.27.232; envelope-from=jeremy@taplink.co; helo=mail.taplink.co; Received: from mail.taplink.co ([50.117.27.232]) by sog-mx-2.v43.ch3.sourceforge.com with smtp (Exim 4.76) id 1WI3l2-0001zG-4R for bitcoin-development@lists.sourceforge.net; Mon, 24 Feb 2014 22:12:16 +0000 Received: from laptop-air ([192.168.168.135]) by mail.taplink.co ; Mon, 24 Feb 2014 14:12:20 -0800 Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes To: "Bitcoin Dev" <bitcoin-development@lists.sourceforge.net>, "Jeff Garzik" <jgarzik@bitpay.com> References: <CAJHLa0PXHY1qisXhN98DMxgp11ouqkzYMBvrTTNOtwX09T1kZg@mail.gmail.com> Date: Mon, 24 Feb 2014 14:12:10 -0800 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Jeremy Spilman" <jeremy@taplink.co> Organization: TapLink Message-ID: <op.xbs3yki1yldrnw@laptop-air> In-Reply-To: <CAJHLa0PXHY1qisXhN98DMxgp11ouqkzYMBvrTTNOtwX09T1kZg@mail.gmail.com> User-Agent: Opera Mail/1.0 (Win32) 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 -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -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: 1WI3l2-0001zG-4R Subject: Re: [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: <bitcoin-development.lists.sourceforge.net> List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>, <mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe> List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development> List-Post: <mailto:bitcoin-development@lists.sourceforge.net> List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help> List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>, <mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe> X-List-Received-Date: Mon, 24 Feb 2014 22:12:17 -0000 On Mon, 24 Feb 2014 09:10:26 -0800, Jeff Garzik <jgarzik@bitpay.com> wrote: > This PR reduces the size to 40 bytes: > https://github.com/bitcoin/bitcoin/pull/3737 Just quickly GLANCED at it, but if I understand correctly how the template matching code works, that will change max size of the <data> to 40 bytes but does not do anything to enforce most-efficient encoding. else if (opcode2 == OP_SMALLDATA) { // small pushdata, <= MAX_OP_RETURN_RELAY bytes if (vch1.size() > MAX_OP_RETURN_RELAY) break; } This code was a bit hard for me to parse since it's not actually requiring any data, just disallowing more than a certain number of bytes of data. So a bare OP_RETURN would be allowed as well, for whatever good that will do. If you want to strictly require no PUSHDATA, perhaps you could do: else if (opcode2 == OP_SMALLDATA) { // small pushdata, <= MAX_OP_RETURN_RELAY bytes if (opcode1 >= OP_PUSHDATA1 || vch1.size() > MAX_OP_RETURN_RELAY) break; } Thanks, Jeremy