Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id C05AECD9 for ; Fri, 26 Feb 2016 23:23:10 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-io0-f171.google.com (mail-io0-f171.google.com [209.85.223.171]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5FBAFEC for ; Fri, 26 Feb 2016 23:23:10 +0000 (UTC) Received: by mail-io0-f171.google.com with SMTP id z135so138260161iof.0 for ; Fri, 26 Feb 2016 15:23:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to; bh=izEvpn1ESo78D5X6mQeQ9mFg4QcNrdTGmcGP9HEbv4c=; b=z3pBPmq0b+hHpjbfXBABg6pff4cClJ+PJzV23/BRpHJKtDhN0JtwMjVJ3GQxBoICtS AhdDiL8UwpidKfYaQ6uvsLAAHAeY1Oc1LTWxiMBZfhzXMylbprqPdt5qLeCWN7/fsJwJ Wm2FSeEdebAaGC5QPXWtBjegMSIkHsL8AGLJ0bUCMTVOiRQl4BEvvtxykIPFGrK64Io+ 3X+0MgKq1ljVR0ac6UJgFwHR8b5zimIKUc6frslztKmTa7CH+t7u3tVyBK3kTMR2rLcH aCxmAnzigy0V75uvXl1d5aEUcy0KA4iYE2Wzaj29ZECQmvftqNI0wnjV0JyKCWr2e+iY LIIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to; bh=izEvpn1ESo78D5X6mQeQ9mFg4QcNrdTGmcGP9HEbv4c=; b=l7Gb+e4By0Bqkdw5fldGwtyoQVYYplSm6FyEOC0aTcfGNWh3vAIr7N8lROik+wBPRE uarQYSMF0rSrXiK3P9B0zRjo2bt8dXyCA8zUp0ovRsjtvAJW+uOnD57enBtq+o/HmIEC cLwFJ/IM/FDgAd3JKF8tTbBSYMEmFA3cxF1YIDSaccmssv91b0GNBI0KQi5sIhCx/pTo 8iqfY0JG6gcxDDt4qDAA++HysM/EdHIVeFCnSB34f2H+O68bSnoe2uA8t3alyVjSWxoP F4MbsCENbckQYL6fhJ9O96lu8KnCLQw2WLBiZnMZtoSQhZ4loIKLFUWixipYCdnQIxN3 tUNw== X-Gm-Message-State: AG10YOTdfQWZ+F6JdalHOt9HwgF6T3DVyohcfFkqqrtEMP1QElIkTwMVZpOW/uBERcWe+tTLkLC8KsInwOOplw== MIME-Version: 1.0 X-Received: by 10.107.14.66 with SMTP id 63mr11112351ioo.150.1456528989900; Fri, 26 Feb 2016 15:23:09 -0800 (PST) Sender: gmaxwell@gmail.com Received: by 10.107.132.75 with HTTP; Fri, 26 Feb 2016 15:23:09 -0800 (PST) In-Reply-To: References: Date: Fri, 26 Feb 2016 23:23:09 +0000 X-Google-Sender-Auth: UUH3S254U3GOns4MZyyes7akKEM Message-ID: From: Gregory Maxwell To: Bitcoin Dev Content-Type: text/plain; charset=UTF-8 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, FREEMAIL_FROM, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: [bitcoin-dev] Fwd: The first successful Zero-Knowledge Contingent Payment X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Feb 2016 23:23:10 -0000 On Fri, Feb 26, 2016 at 11:06 PM, Sergio Demian Lerner wrote: > Congratulations! > > It a property of the SKCP system that the person who performed the trusted > setup cannot extract any information from a proof? > > In other words, is it proven hard to obtain information from a proof by the > buyer? Yes, the secrecy is information theoretic (assuming no implementation bugs); beyond the truth of the outcome. This holds even if the initialization is malicious. The soundness of this scheme is computational-- we're trusting a deep stack of cryptographic assumptions that the proofs cannot be forged.