From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4B65EC016F for ; Thu, 11 Jun 2020 21:02:48 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 3B19787B74 for ; Thu, 11 Jun 2020 21:02:48 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id UWn4Tdo7X4ZJ for ; Thu, 11 Jun 2020 21:02:46 +0000 (UTC) X-Greylist: delayed 00:15:16 by SQLgrey-1.7.6 Received: from mail-qv1-f51.google.com (mail-qv1-f51.google.com [209.85.219.51]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 5242787B61 for ; Thu, 11 Jun 2020 21:02:46 +0000 (UTC) Received: by mail-qv1-f51.google.com with SMTP id dp10so3320550qvb.10 for ; Thu, 11 Jun 2020 14:02:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=woobling.org; s=google; h=mime-version:from:date:message-id:subject:to; bh=WjlBV7MnKKJhKK1KiiNhw1ubyU3eFcIurQ46muZNZg4=; b=JF7dfkjAeGb+QiA+Kath5uQjroIrx8JsmFPAKWW/jCJ8GcGhMIIXS5AH/0VyECvclg 6Ye+xM8RZEIwenOZ2fa/UW2psUVzDam76ysGS3g237TJiDyJbJBnBLUFWMqzYR82jUrE MbGEd+eiirGLXjSXWaQXdIztPJ4m3Mn7Dos5M= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=WjlBV7MnKKJhKK1KiiNhw1ubyU3eFcIurQ46muZNZg4=; b=cO5Y3Rioxjr+y148GQUvKS56euLcps9pjN1f3AVDVxbi5sdTGGn8hYDu8m+4I+VWC/ /tKQO2wmFaTyEM7JwNEAjrtA3z9qkAKMepUTeBA7aHtLU4CoeX9cstcdCq52/AGq2A8e 8LqQw3e6+tWeOSqHKqDhpKLchibcpFG5JMzfALNdQiw4BJIIRBXxY+nhMBIxG5dVdcLd fzYEQLRI581OXWBTv6ZScda058OkFKNEbN/g6qg5CaEY91U9wH/3XPUH31dZqGcMXQPw iZkoovoTddYmRlzT6fMc/9MM2Vn5f4Y4A/p0rLQk9WlpGjaEVgJCpf1ZRJp8aBrtBKcX VGMQ== X-Gm-Message-State: AOAM531oZM/0TSWdNkJosEjFkTACG2y1HrImB1w/TEGdtYxfk2xhtWGn rjRDw+EgeZrTdEDYLpF6vrYJXeBCWktH4TZCSk/ky3Q3RRc= X-Google-Smtp-Source: ABdhPJyaOFr7Dz9/SfrdHSY1Ba27Dt53CRS3OVXQloexFl9LT0znAGh5dLmPl1s8u0tyreNcebU1XG2dTyr2cbmpXtg= X-Received: by 2002:aa7:868f:: with SMTP id d15mr9243813pfo.166.1591908019099; Thu, 11 Jun 2020 13:40:19 -0700 (PDT) MIME-Version: 1.0 From: Yuval Kogman Date: Thu, 11 Jun 2020 20:40:07 +0000 Message-ID: To: Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Mailman-Approved-At: Thu, 11 Jun 2020 21:10:14 +0000 Subject: [bitcoin-dev] WabiSabi: a building block for coordinated CoinJoins X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Jun 2020 21:02:48 -0000 Hi, As part of research into how CoinJoins in general and Wasabi in particular can be improved, we'd like to share a new building block we're calling WabiSabi, which utilizes keyed verification anonymous credentials instead of blind signatures to verify the honest participation of users in centrally coordinated CoinJoin protocols. Blind signatures have been used to facilitate centrally coordinated CoinJoins, but require standard denominations, each associated with a key, because blind signatures can only convey a single bit of information from the signer to the verifier (both roles are the coordinator in this setting). Anonymous credentials carry attributes, and in our case these are homomorphic value commitments as in Confidential Transactions. Note that this is an early draft with a deliberately narrow scope, and only introduces this abstract building block. At this stage we'd like to solicit feedback and criticism about our scheme and inputs with regards to its potential applications before proceeding. We do not not (yet) address the structure of the CoinJoin transactions, fee structures, or other implementation details, but discussion of these aspects is welcome. The repository is https://github.com/zkSNACKs/WabiSabi, and the latest version is available here: https://github.com/zkSNACKs/WabiSabi/releases/latest/download/WabiSabi.pdf