Return-Path: <5700er@gmx.com> Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4BCFDC0001 for <bitcoin-dev@lists.linuxfoundation.org>; Sun, 21 Feb 2021 23:28:52 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 3632B82476 for <bitcoin-dev@lists.linuxfoundation.org>; Sun, 21 Feb 2021 23:28:52 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id noBih-Iow8EH for <bitcoin-dev@lists.linuxfoundation.org>; Sun, 21 Feb 2021 23:28:51 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mout-xforward.gmx.net (mout-xforward.gmx.net [82.165.159.41]) by hemlock.osuosl.org (Postfix) with ESMTPS id 7D88187031 for <bitcoin-dev@lists.linuxfoundation.org>; Sun, 21 Feb 2021 23:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1613950125; bh=fwljxx+tqzrkMG27ndYM870+KCTKsNqVtc6+hgZ/R04=; h=X-UI-Sender-Class:From:To:Subject:Date:In-Reply-To:References; b=KKfC0PJUJXAfdJYGMZKwtnXJ6xgb8wuSKFv87bsC1hhU9fMGkA8uqJKg7D50s+Zs1 T3UA5UkCv60wCPO/k498BlqOuu0/hsLOY0MYTiT1KD7sBLss/0dYA2fvAryqyNQmAX b47PScpUiepW5U9bbRFiycGSAx8zqibg79sDXpmE= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [68.207.10.113] ([68.207.10.113]) by web-mail.gmx.net (3c-app-mailcom-bs10.server.lan [172.19.170.178]) (via HTTP); Mon, 22 Feb 2021 00:28:44 +0100 MIME-Version: 1.0 Message-ID: <trinity-6ade29b2-2d87-490b-8d01-b5c754c3f652-1613950124890@3c-app-mailcom-bs10> From: Herman Puller <5700er@gmx.com> To: belcher@riseup.net, bitcoin-dev@lists.linuxfoundation.org Content-Type: text/html; charset=UTF-8 Date: Mon, 22 Feb 2021 00:28:44 +0100 Importance: normal Sensitivity: Normal In-Reply-To: <5fcab0fc-6135-7587-7b3c-a314ccd099ca@riseup.net> References: <5fcab0fc-6135-7587-7b3c-a314ccd099ca@riseup.net> X-UI-Message-Type: mail X-Priority: 3 X-Provags-ID: V03:K1:XYVAPr4vcmlF1lhG01vk3ps8fr5dtuT7ctQK4TUKnSvSFnZGvsGtIpKclp0jGmTM6L0UH wc+V6MgHPvr3XDoYCWW2mqgi3vf8aP6A3R7dHU4Ew3U12QN0Di1wIv8L+jIkw+NYn2grf8TFxwLX 8KLFCnZxumz8F1lJv+GV5iy1tKfc5pca950Ue1ib9fPpNeFtXY03g0D8GghcfTA/Kz4kZwFSI2N5 GOyO4v8jxoP/pgQXrg55a2mh6lU70cWJEbPy03ubdTz9Aw2nR9RAbNpwb+ciZRTxg8qz8vnkBS8E hc= X-UI-Out-Filterresults: junk:10;V03:K0:/7s6oVpBP/A=:y2XWGwPdByYfK4zA2COPJtFr L0Fqk1vT8dIECjzRfmdpXldCPApd/HtdmffdaFtUzGIBsQYIc/vNpKHZ5kNLeM0o7wSnu7Id5 xOpQKs+iSdphzk0sthf/FkGkV/SqPTxo/FsGhUF6Wi9FJ4cAI3MdJ2m47nQ1nH/eEHv7Ds3bA oYM9HxADgeq9r6ak5sdCBRLkUwCx3ku7YCee5PCEcQUZSNzoPoLsfrOXfMnUVoP5LQRscy1T6 0xsqfwaofwMDjK7b4lTj66KBv+N04VRCLk51UNdbq4Xx6rqbsd6Jd8rsKhL5iCgel4CEHAUoq UA/uVLZCsEWHsfROkdAJI8kJkLpmPG+e9Qb9vZVXkdbUec0G+sPwbe/GI5D8IXVParBz99WK4 H/x5RYw9D/fF5C04o7i1kJ2gDESJKxr+0Tlvox+d/YEktAQhaCSwwyGThm6v5MqC8Ek2WaNmv w61xj88h4Pha+aMIsBorLw5yqRNbtHmKKlITENXwNgBj2tmUmS+njTzWA7o6HJqAAvjqV9QVf UXLFU5dkdzWVVAVpeJSf+vysG5JqVFZNxx1mWC4bmlcux2j0m4xRyUKC0iSze2GWA2DlABHOF +fSAR2+XWh8V1cv9R09u9w2CLSR4JmqJ55bq/HBJRePBkMD8AayJeRobwRgJkBcA2BjbCyQ1K HqnbCGn43sjf1/iTRMETcjX X-Mailman-Approved-At: Mon, 22 Feb 2021 08:02:33 +0000 Subject: Re: [bitcoin-dev] Teleport Transactions: A CoinSwap implementation for Bitcoin X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion <bitcoin-dev.lists.linuxfoundation.org> List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>, <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe> List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/> List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org> List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help> List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>, <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe> X-List-Received-Date: Sun, 21 Feb 2021 23:28:52 -0000 <html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div> </div> <div>42 pieces waiting for me and this 1 interests me most, yet not a single comment to it. Must just be me, I guess. Anyway, please keep plugging away, Chris. And thanks. <div> <div name="quote" style="margin:10px 5px 5px 10px; padding: 10px 0 10px 10px; border-left:2px solid #C3D9E5; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"> <div style="margin:0 0 10px 0;"><b>Sent:</b> Wednesday, February 17, 2021 at 4:27 PM<br/> <b>From:</b> "Chris Belcher via bitcoin-dev" <bitcoin-dev@lists.linuxfoundation.org><br/> <b>To:</b> bitcoin-dev@lists.linuxfoundation.org<br/> <b>Subject:</b> [bitcoin-dev] Teleport Transactions: A CoinSwap implementation for Bitcoin</div> <div name="quoted-content">Suppose Alice has bitcoins and wants to send them with maximal privacy,<br/> so she creates a special kind of transaction. For anyone looking at the<br/> blockchain her transaction appears completely normal with her coins<br/> seemingly going from bitcoin address A to address B. But in reality her<br/> coins end up in address Z which is entirely unconnected to either A or B.<br/> <br/> Now imagine another user, Carol, who isn't too bothered by privacy and<br/> sends her bitcoin using a regular wallet. But because Carol's<br/> transaction looks exactly the same as Alice's, anybody analyzing the<br/> blockchain must now deal with the possibility that Carol's transaction<br/> actually sent her coins to a totally unconnected address. So Carol's<br/> privacy is improved even though she didn't change her behaviour, and<br/> perhaps had never even heard of this software.<br/> <br/> In a world where advertisers, social media and other companies want to<br/> collect all of Alice's and Carol's data, such privacy improvement would<br/> be incredibly valuable. And also the doubt added to every transaction<br/> would greatly boost the fungibility of bitcoin and so make it a better<br/> form of money.<br/> <br/> This undetectable privacy can be developed today by implementing<br/> CoinSwap. The software could be standalone as a kind of bitcoin mixing<br/> app, but it could also be a library that existing wallets can implement<br/> allowing their users to send Bitcoin transactions with much greater privacy.<br/> <br/> For the last few months I've been working on implementing this project.<br/> Here it is:<br/> <br/> <br/> <a href="https://github.com/bitcoin-teleport/teleport-transactions/" target="_blank">https://github.com/bitcoin-teleport/teleport-transactions/</a><br/> <br/> <br/> The project can create multi-transaction CoinSwaps (intended to avoid<br/> amount correlation), and multi-hop CoinSwaps (intended to stop one<br/> single maker being able to unmix a taker's CoinSwap).<br/> <br/> Just for fun I created a 5-hop CoinSwap on testnet. Here are the<br/> transaction IDs of each funding transaction. Each hop has 3 individual<br/> transactions.<br/> <br/> taker's outgoing txes:<br/> <a href="https://blockstream.info/testnet/tx/f45349bd279bea20b8b218300f8e2416abf28f3858470ad8c5eb2f6cd5ec10a9" target="_blank">https://blockstream.info/testnet/tx/f45349bd279bea20b8b218300f8e2416abf28f3858470ad8c5eb2f6cd5ec10a9</a><br/> <a href="https://blockstream.info/testnet/tx/40ea5c9e478b66fa3f615c2b8d3accfd69308443d90a5353de669767cb02c51f" target="_blank">https://blockstream.info/testnet/tx/40ea5c9e478b66fa3f615c2b8d3accfd69308443d90a5353de669767cb02c51f</a><br/> <a href="https://blockstream.info/testnet/tx/8fe245e9c433127af4df8ff8853650808e3281fed7de6bfda62066a3fd3ad36e" target="_blank">https://blockstream.info/testnet/tx/8fe245e9c433127af4df8ff8853650808e3281fed7de6bfda62066a3fd3ad36e</a><br/> <br/> maker[0] funding txes:<br/> <a href="https://blockstream.info/testnet/tx/3d9b879866ad136f9fe6e80599e1b97d610b6330be3ab4aa7df4161fce1e41d4" target="_blank">https://blockstream.info/testnet/tx/3d9b879866ad136f9fe6e80599e1b97d610b6330be3ab4aa7df4161fce1e41d4</a>,<br/> <a href="https://blockstream.info/testnet/tx/fa11e778d135be28b4e35498fc668c5aba7c70dcc43334b39e7488bd1259e8be" target="_blank">https://blockstream.info/testnet/tx/fa11e778d135be28b4e35498fc668c5aba7c70dcc43334b39e7488bd1259e8be</a>,<br/> <a href="https://blockstream.info/testnet/tx/a7713452bab711c09be83a8c630fb91127771ed99cf15b528eacd28b00ba6b20" target="_blank">https://blockstream.info/testnet/tx/a7713452bab711c09be83a8c630fb91127771ed99cf15b528eacd28b00ba6b20</a>,<br/> <br/> maker[1] funding txes:<br/> <a href="https://blockstream.info/testnet/tx/245e1e87d83a4bef06ceb8933c758137ee2f7ba7aa66800ebb7103707d5de5f7" target="_blank">https://blockstream.info/testnet/tx/245e1e87d83a4bef06ceb8933c758137ee2f7ba7aa66800ebb7103707d5de5f7</a>,<br/> <a href="https://blockstream.info/testnet/tx/15727b91e09a80634587f6210bdcba8808b93e4a780c55dd113ee85314db45c4" target="_blank">https://blockstream.info/testnet/tx/15727b91e09a80634587f6210bdcba8808b93e4a780c55dd113ee85314db45c4</a>,<br/> <a href="https://blockstream.info/testnet/tx/94e4e4e9e8fc2012158ed068145c8b883c295b37f5b3b6cba7a21c229d4da103" target="_blank">https://blockstream.info/testnet/tx/94e4e4e9e8fc2012158ed068145c8b883c295b37f5b3b6cba7a21c229d4da103</a>,<br/> <br/> maker[2] funding txes:<br/> <a href="https://blockstream.info/testnet/tx/1384d58e534543e22e4f23a367728bff12177ee9af01b036c397cfca9bbe2eb8" target="_blank">https://blockstream.info/testnet/tx/1384d58e534543e22e4f23a367728bff12177ee9af01b036c397cfca9bbe2eb8</a>,<br/> <a href="https://blockstream.info/testnet/tx/eff3b1367f403c13927ddcb01c6d3c5c0d46076f7cb4419f8a18d6b62d884540" target="_blank">https://blockstream.info/testnet/tx/eff3b1367f403c13927ddcb01c6d3c5c0d46076f7cb4419f8a18d6b62d884540</a>,<br/> <a href="https://blockstream.info/testnet/tx/617c52caec2f7f17f3ebd1cab80233cdc1b414591f1cc49affbd828ffec10278" target="_blank">https://blockstream.info/testnet/tx/617c52caec2f7f17f3ebd1cab80233cdc1b414591f1cc49affbd828ffec10278</a>,<br/> <br/> maker[3] funding txes (also taker's incoming txes):<br/> <a href="https://blockstream.info/testnet/tx/8fde61974a4e0801ae5b76b620e2effd6c837310c1bd76d738216451ae1226e3" target="_blank">https://blockstream.info/testnet/tx/8fde61974a4e0801ae5b76b620e2effd6c837310c1bd76d738216451ae1226e3</a>,<br/> <a href="https://blockstream.info/testnet/tx/6491b85ef73a8f88e276a9b0f951c09e0367851a83aa49ffee8f8ad095f50de2" target="_blank">https://blockstream.info/testnet/tx/6491b85ef73a8f88e276a9b0f951c09e0367851a83aa49ffee8f8ad095f50de2</a>,<br/> <a href="https://blockstream.info/testnet/tx/363b6803b7e3ed45472277448ce9938e3e73167a67762d6a9ac621243b8db019" target="_blank">https://blockstream.info/testnet/tx/363b6803b7e3ed45472277448ce9938e3e73167a67762d6a9ac621243b8db019</a>,<br/> <br/> <br/> The so-called taker organized the whole thing. They decided what the<br/> CoinSwap amount should be (0.05 tBTC in this case), decided which makers<br/> to route over depending on their fees, how many transactions and makers<br/> there would be. The only thing the makers do is follow the protocol and<br/> collect their CoinSwap fees, they are not meant to even know their<br/> position in the route. Because the taker chose how much bitcoin to<br/> coinswap and when, they paid a fee to each maker to provide an incentive<br/> for the makers to keep the software running.<br/> <br/> To a passive observer of the blockchain a single-hop CoinSwap is as<br/> private as a multi-hop, so I suspect in practice most users will just<br/> create 2-hop CoinSwaps.<br/> <br/> The project is still a work in progress. All kinds of attacks are<br/> possible right now, so the it shouldn't be used on mainnet with real<br/> money yet. Also right now the CoinSwap addresses created by the project<br/> appear as 2-of-2 multisignature addresses, but the plan is to use<br/> ECDSA-2P which will make them look the same as regular single-signature<br/> addresses which is needed before the thing massively improves privacy<br/> and fungibility.<br/> <br/> CoinSwap is the next generation of bitcoin on-chain privacy tech. It<br/> improves on CoinJoin because it breaks the transaction graph, and even<br/> improves the privacy of people who don't use it. CoinSwap also uses less<br/> block space for the same privacy and therefore is cheaper in miner fees.<br/> <br/> Links:<br/> * Design document:<br/> <a href="https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964" target="_blank">https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964</a><br/> * Discussion: `##coinswap` IRC channel on the freenode network<br/> _______________________________________________<br/> bitcoin-dev mailing list<br/> bitcoin-dev@lists.linuxfoundation.org<br/> <a href="https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" target="_blank">https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev</a></div> </div> </div> </div></div></body></html>