From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1RjhJT-00020p-9d for bitcoin-development@lists.sourceforge.net; Sun, 08 Jan 2012 01:12:43 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.212.175 as permitted sender) client-ip=209.85.212.175; envelope-from=gavinandresen@gmail.com; helo=mail-wi0-f175.google.com; Received: from mail-wi0-f175.google.com ([209.85.212.175]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1RjhJS-0003mC-3A for bitcoin-development@lists.sourceforge.net; Sun, 08 Jan 2012 01:12:42 +0000 Received: by wibhq7 with SMTP id hq7so2932198wib.34 for ; Sat, 07 Jan 2012 17:12:36 -0800 (PST) MIME-Version: 1.0 Received: by 10.180.72.162 with SMTP id e2mr15768787wiv.8.1325985155897; Sat, 07 Jan 2012 17:12:35 -0800 (PST) Received: by 10.223.156.77 with HTTP; Sat, 7 Jan 2012 17:12:35 -0800 (PST) In-Reply-To: <1325977874.57604.YahooMailNeo@web121006.mail.ne1.yahoo.com> References: <1325956875.73286.YahooMailNeo@web121006.mail.ne1.yahoo.com> <1325977874.57604.YahooMailNeo@web121006.mail.ne1.yahoo.com> Date: Sat, 7 Jan 2012 20:12:35 -0500 Message-ID: From: Gavin Andresen To: Amir Taaki 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 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (gavinandresen[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: 1RjhJS-0003mC-3A Cc: "bitcoin-development@lists.sourceforge.net" Subject: Re: [Bitcoin-development] Pull 748 pay to script hash 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, 08 Jan 2012 01:12:43 -0000 > what is the purpose behind counting the number of sig ops after you have executed the script in ConnectInputs? > Seems like it would be too late then. The purpose is to comply with the "a block shall not contain more than MAX_BLOCK_SIGOPS (20,000)" rule, under both the old way of counting (look at the scriptPubKeys and count CHECKMULTISIGs as 20 sigops no matter what) and the new way (look at both scriptPubKeys and pay-to-script-hash scripts in the scriptSig, but count CHECKMULTISIGS preceded by OP_1/2/3/... as 1/2/3 operations). RE: too late: Excellent point. I'll refactor ConnectInputs further, and do something like: FetchInputs() AreInputsStandard() <-- reject from memory pool if nonstanard ComputeSigOps() ComputeFees() <-- reject if too little fees per byte / sigop ConnectInputs() Pieter's compressed-public-keys patch (which was just pulled) interacts with pay-to-script-hash to make ECDSA denial-of-service attempts less expensive; I think we need to think hard again about transaction fees before releasing 0.6, and maybe tweak the fee policy so denial-of-service attacks using compressed public keys and 1-of-3 CHECKMULTISIG transactions is expensive enough to deter would-be attackers. -- -- Gavin Andresen