Return-Path: Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7595BC0032 for ; Mon, 24 Jul 2023 15:39:13 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 4FBCE40443 for ; Mon, 24 Jul 2023 15:39:13 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 4FBCE40443 Authentication-Results: smtp2.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20221208 header.b=CZxtp1Pj X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.099 X-Spam-Level: X-Spam-Status: No, score=-2.099 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KJ2dI54cIo0w for ; Mon, 24 Jul 2023 15:39:12 +0000 (UTC) Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by smtp2.osuosl.org (Postfix) with ESMTPS id 87E584031E for ; Mon, 24 Jul 2023 15:39:12 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 87E584031E Received: by mail-wm1-x32a.google.com with SMTP id 5b1f17b1804b1-3fbc0609cd6so34881625e9.1 for ; Mon, 24 Jul 2023 08:39:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1690213150; x=1690817950; h=content-transfer-encoding:in-reply-to:references:to :content-language:subject:user-agent:mime-version:date:message-id :from:from:to:cc:subject:date:message-id:reply-to; bh=+NaJBa9sPRsgpYwXZiApZmz8Ln1Vpn4KdNU8ByrLHGk=; b=CZxtp1Pjgoa/KyWdbC4nCPCCss8Xl6YH8lPbGxvuHmHI8v9qfVkc8090HVd+C06zMF kzKTii0HlWwa2la3RFr9NRqV+VG3GHviYro7iwBhMvO+BR8PbYwAW9cP1MEPvo/udPJS DzKCiLOqgQERF2YBI+yISBcPjpB4053XPSpJLnk6K2AWmF+ts20y+qAxzLnHo5vlyDev e5A900pL5Wg0amT5Z8q/mlQmP7WSjLojYCKpwTUjNTrO8sVF1qIT5igcyYZwibbZZT56 ZMwFf/CL1qoTIqMye0hJZx84hthlCzolAHzOfXr//toN+ckYvmv9h8pCOlkd2i/+8FGA 4GZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690213150; x=1690817950; h=content-transfer-encoding:in-reply-to:references:to :content-language:subject:user-agent:mime-version:date:message-id :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+NaJBa9sPRsgpYwXZiApZmz8Ln1Vpn4KdNU8ByrLHGk=; b=O9pnZAdhJubwf7juIu0Gc4PvClydU+KVrxQ2s85ijTrzI9vt9QyOyYU9ayBD/1YNHG F9y6+aGzx3KRXioNGnp8Gj5tD1Mb+sA6AXQ4e6NMsqdPP5c6+KsPDVMOujbgJoSZWHsl xX2zULO5E+MOiZdYF29S3T8QHrD5Gdxs49qjnaVhUB0yekQmN/2hPTuo7L0k9rr61yYu /54wqv/qRsJh+mOHKkb0T6dghiKvmdMq9IOeDr4weirvpZFYXvyIQ2RaqsDIrCzcO/8q oomiaPV1HJg9Uu4GlXpMAj0Jp7z+RWtN5VHGwp+n0+XHNEIzKsQgW7ozLjmjXQirdX2i DiMQ== X-Gm-Message-State: ABy/qLbIRpKlBuU5H3bp3iPf/DTVhvzyh4AKWSWWCm0lbGLVRLLPzgeC +vLtH/uvLufGzFtpKBpUxDE= X-Google-Smtp-Source: APBJJlHm8V8DSp0t6MBGNMJNZUPOqAdXmgjRPXTzgOYNm4dOPFopXyRdhd66h/LloGQwbiqAHkWGwQ== X-Received: by 2002:a05:600c:20d1:b0:3fd:1daf:abd8 with SMTP id y17-20020a05600c20d100b003fd1dafabd8mr5577279wmm.40.1690213150388; Mon, 24 Jul 2023 08:39:10 -0700 (PDT) Received: from [10.11.10.42] (p50879c84.dip0.t-ipconnect.de. [80.135.156.132]) by smtp.googlemail.com with ESMTPSA id k22-20020a7bc316000000b003fd2d33ea53sm6531289wmj.14.2023.07.24.08.39.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 24 Jul 2023 08:39:10 -0700 (PDT) From: Jonas Nick X-Google-Original-From: Jonas Nick Message-ID: Date: Mon, 24 Jul 2023 15:39:09 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: Tom Trevethan , Bitcoin Protocol Discussion References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Mon, 24 Jul 2023 15:42:40 +0000 Subject: Re: [bitcoin-dev] Blinded 2-party Musig2 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: Mon, 24 Jul 2023 15:39:13 -0000 > Party 1 never learns the final value of (R,s1+s2) or m. Actually, it seems like a blinding step is missing. Assume the server (party 1) received some c during the signature protocol. Can't the server scan the blockchain for signatures, compute corresponding hashes c' = H(R||X||m) as in signature verification and then check c == c'? If true, then the server has the preimage for the c received from the client, including m.