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 1RpVhQ-00078G-EA for bitcoin-development@lists.sourceforge.net; Tue, 24 Jan 2012 02:01:28 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.212.47 as permitted sender) client-ip=209.85.212.47; envelope-from=kungfoobar@gmail.com; helo=mail-vw0-f47.google.com; Received: from mail-vw0-f47.google.com ([209.85.212.47]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1RpVhP-0002UT-Fs for bitcoin-development@lists.sourceforge.net; Tue, 24 Jan 2012 02:01:28 +0000 Received: by vbnl22 with SMTP id l22so3199407vbn.34 for ; Mon, 23 Jan 2012 18:01:22 -0800 (PST) Received: by 10.52.173.211 with SMTP id bm19mr5088717vdc.2.1327370480220; Mon, 23 Jan 2012 18:01:20 -0800 (PST) MIME-Version: 1.0 Received: by 10.52.35.229 with HTTP; Mon, 23 Jan 2012 18:00:59 -0800 (PST) From: Alberto Torres Date: Tue, 24 Jan 2012 03:00:59 +0100 Message-ID: To: bitcoin-development@lists.sourceforge.net 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 (kungfoobar[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: 1RpVhP-0002UT-Fs Subject: [Bitcoin-development] [PROPOSAL] Merkle tree of unspent transactions (MTUT), for serverless thin clients and self-verifiable prunned blockchain. 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: Tue, 24 Jan 2012 02:01:28 -0000 Hello, I've written this proposal. C&P of the overview: Satoshi's original paper describes a way of prunning spent transactions in the blockchain to save storage space while it remains consistent and verifiable, but it's useless for partial blockchain downloads: while you can know if a given transaction is in the blockchain, you can't know if it has been spent in a subsequent transaction. This proposal describes how to add a hash-tree based check in the blockchain that allows to verify if a transaction is unspent without downloading and checking all the blockchain. The idea is not new, but at the time of this writing there isn't any technical description of how this should be done. Aditionally, this solution is rather simple. https://en.bitcoin.it/wiki/User:DiThi/MTUT Cheers -- Alberto Torres Ruiz (a.k.a. DiThi)