Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WxAVf-0000Xy-UZ for bitcoin-development@lists.sourceforge.net; Wed, 18 Jun 2014 07:42:20 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.213.174 as permitted sender) client-ip=209.85.213.174; envelope-from=laanwj@gmail.com; helo=mail-ig0-f174.google.com; Received: from mail-ig0-f174.google.com ([209.85.213.174]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WxAVe-00062B-4N for bitcoin-development@lists.sourceforge.net; Wed, 18 Jun 2014 07:42:19 +0000 Received: by mail-ig0-f174.google.com with SMTP id l13so1883446iga.1 for ; Wed, 18 Jun 2014 00:42:12 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.42.83.7 with SMTP id f7mr229278icl.65.1403077332189; Wed, 18 Jun 2014 00:42:12 -0700 (PDT) Received: by 10.64.60.195 with HTTP; Wed, 18 Jun 2014 00:42:12 -0700 (PDT) In-Reply-To: References: Date: Wed, 18 Jun 2014 09:42:12 +0200 Message-ID: From: Wladimir To: Gavin Andresen Content-Type: text/plain; charset=UTF-8 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 (laanwj[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: 1WxAVe-00062B-4N Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Proposal: relax the IsStandard rules for P2SH transactions 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, 18 Jun 2014 07:42:20 -0000 On Tue, Jun 17, 2014 at 9:40 PM, Gavin Andresen wrote: > Assuming there is rough consensus, I'll make this a pull request (see > https://github.com/gavinandresen/bitcoin-git/tree/relax_isstandard for code > changes). > > ---- > > Now that we are finally starting to see the use of multi-signature and other > more complicated transaction forms in applications I think it is time to > open up the "IsStandard" transaction rules on the main Bitcoin network. Agreed! > Discussion > ---------- > Allowing any P2SH Script would allow an attacker to craft a single standard > transaction output that requires on the order of 200 ECDSA signature > checking operations to validate-- an order of magnitude more than is > currently allowed. Therefore I am proposing that we keep the current > 15-signature-checking-operations-per-transaction-output limit in place, but > allow any combination of enabled Script opcodes. So, for example, you might > have a P2SH Script that is redeemed with 2-of-2 OR 2-of-3 using: Soungs good to me - to lift the restrictions and increase flexibility, but also to be a careful and keep the DoS limits. > The reference implementation's wallet will still only recognize P2SH > transactions that use one of the standard transaction forms. To actually USE > a new transaction form will require specialized wallets or specialized > applications. That's of course completely separate. As we all know, most wallet innovation doesn't happen in the reference implementation wallet, and it should not be used as the guide here. Wladimir