Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1QwF7o-0006Bf-WA for bitcoin-development@lists.sourceforge.net; Wed, 24 Aug 2011 15:12:17 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.218.47 as permitted sender) client-ip=209.85.218.47; envelope-from=gavinandresen@gmail.com; helo=mail-yi0-f47.google.com; Received: from mail-yi0-f47.google.com ([209.85.218.47]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1QwF7o-00089p-0t for bitcoin-development@lists.sourceforge.net; Wed, 24 Aug 2011 15:12:16 +0000 Received: by yia28 with SMTP id 28so1152754yia.34 for ; Wed, 24 Aug 2011 08:12:10 -0700 (PDT) MIME-Version: 1.0 Received: by 10.142.193.6 with SMTP id q6mr2652971wff.164.1314198730161; Wed, 24 Aug 2011 08:12:10 -0700 (PDT) Received: by 10.142.147.17 with HTTP; Wed, 24 Aug 2011 08:12:10 -0700 (PDT) Date: Wed, 24 Aug 2011 11:12:10 -0400 Message-ID: From: Gavin Andresen To: Bitcoin Dev Content-Type: text/plain; charset=ISO-8859-1 X-Spam-Score: -1.3 (-) 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 0.3 AWL AWL: From: address is in the auto white-list X-Headers-End: 1QwF7o-00089p-0t Subject: [Bitcoin-development] New standard transaction types: time to schedule a blockchain split? 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, 24 Aug 2011 15:12:17 -0000 It seems to me the fastest path to very secure, very-hard-to-lose bitcoin wallets is multi-signature transactions. To organize this discussion: first, does everybody agree? ByteCoin pointed to a research paper that gives a scheme for splitting a private key between two people, neither of which every knows the full key, but, together, both can DSA-sign transactions. That's very cool, but it involves high-end cutting-edge crypto like zero-knowledge proofs that I know very little about (are implementations available? are they patented? have they been thoroughly vetted/tested? etc). So I'm assuming that is NOT the fastest way to solving the problem. If anybody has some open-source, patent-free, thoroughly-tested code that already does DSA-key-splitting, speak up please. I've been trying to get consensus on low-level 'standard' transactions for transactions that must be signed by 2 or 3 keys; current draft proposal is here: https://gist.github.com/39158239e36f6af69d6f and discussion on the forums here: https://bitcointalk.org/index.php?topic=38928.0 ... and there is a pull request that is relevant here: https://github.com/bitcoin/bitcoin/pull/319 I still think it is a good idea to enable a set of new 'standard' multisignature transactions, so they get relayed and included into blocks. I don't want to let "the perfect become the enemy of the good" -- does anybody disagree? The arguments against are that if the proposed standard transactions are accepted, then the next step is to define a new kind of bitcoin address that lets coins be deposited into a multisignature-protected wallet. And those new as-yet-undefined bitcoin addresses will have to be 2 or 3 times as big as current bitcoin addresses, and will be incompatible with old clients. So, if we are going to have new releases that are incompatible with old clients why not do things right in the first place, implement or enable opcodes so the new bitcoin addresses can be small, and schedule a block chain split for N months from now. My biggest worry is we'll say "Sure, it'll only take a couple days to agree on how to do it right" and six months from now there is still no consensus on exactly which digest function should be used, or whether or not there should be a new opcode for arbitrary boolean expressions involving keypairs. And people's wallets continue to get lost or stolen. -- -- Gavin Andresen