Return-Path: Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 13533C002D for ; Sun, 17 Jul 2022 20:45:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id E06C041574 for ; Sun, 17 Jul 2022 20:45:35 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org E06C041574 Authentication-Results: smtp4.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=aIaNycaq X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.1 X-Spam-Level: X-Spam-Status: No, score=-2.1 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, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ulA7PeAitzbB for ; Sun, 17 Jul 2022 20:45:35 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org C8CB141554 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by smtp4.osuosl.org (Postfix) with ESMTPS id C8CB141554 for ; Sun, 17 Jul 2022 20:45:34 +0000 (UTC) Received: by mail-ed1-x52c.google.com with SMTP id r6so12920554edd.7 for ; Sun, 17 Jul 2022 13:45:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:message-id:date:mime-version:user-agent:subject :content-language:to:references:in-reply-to :content-transfer-encoding; bh=FT1620G+82fyyrzv+FiNV29eG8PdWSHi+PuceGsDiCk=; b=aIaNycaq5aRHp53n3lZmqxNu4q33ftUpyDrACubxwZ+yZPN0T3Gunv9bfyC+rNIec1 hrtEkLHANg2yFyRA2jWi3wUiCrlIfWGl1ujC6Ur42IOxDua+OFG0pSNRievzuDCUsxfF Pl9sS8yhocRrzoXPQuxpNjp4fLqtLcLori5p2/Xr2DsZnJ5+KnjK1ILim4k+IyR/H4Ur jDUDgZVYtWsRNYtoDNyAAPYMBkwu0Mk695MBlrvxwyr7+x9yjnQv842K2Vc1ctgbMSI5 s+v/+RfGDQfNf6UJosdNl4LhHVrsRpww0fqH6m/JBsL8f31bzgsKW56nZtBCBCd93RVA JD9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:message-id:date:mime-version:user-agent :subject:content-language:to:references:in-reply-to :content-transfer-encoding; bh=FT1620G+82fyyrzv+FiNV29eG8PdWSHi+PuceGsDiCk=; b=Gq8/n/9Qkx38Vb+0K4yVe5wXvCWKTEtO8faBfAv+QPgU5HDumxW+UW2qbb5qmd+xwi DTPKcuwN4lXKgMVuGS5W/jrwgHiKCJVafSA6I6yH1mVqcB6ewEaihnEBtFHoPeWD+uBm 5EFyaQBgF15KwTkeGqj9wGvre4oxR+ZVZLLLEaAI7FJIu1EA6P3jyfoL6LA1GZ0Qz0gV i/d5fa5LNk0tjM2WPGP2K5DPWdJBnCjGbIsxY09QRq05CVmauVrPeB60fCFNeiiHquBR iplEF6Y+PiY2af+xHy9Neo5yTeG4IwaPmu5P1CmAYkJKRy0ypjsjXFdJvdLIBTguGEIf tJCg== X-Gm-Message-State: AJIora85YZab2CGSeq2Wh+tfbP8IPMdZ5ZNQDkEKoPdm1Y+94D5bvejW FnGVOBhZ6yrcMM3T3+qEZFQ= X-Google-Smtp-Source: AGRyM1tCgeCrmRtseLnThm5atV5IKXD0NhwtRkY9uRD8KtEQV5QGG5AbsUscIUs40xDjWH77dAAO3w== X-Received: by 2002:a05:6402:249d:b0:437:8622:6de8 with SMTP id q29-20020a056402249d00b0043786226de8mr33547935eda.113.1658090732835; Sun, 17 Jul 2022 13:45:32 -0700 (PDT) Received: from [10.12.10.3] ([46.166.182.100]) by smtp.googlemail.com with ESMTPSA id f24-20020a056402069800b004316f94ec4esm7288169edy.66.2022.07.17.13.45.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 17 Jul 2022 13:45:32 -0700 (PDT) From: Jonas Nick X-Google-Original-From: Jonas Nick Message-ID: <2f511890-23a7-882a-332c-85cda02fba7a@gmail.com> Date: Sun, 17 Jul 2022 20:48:11 +0000 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Content-Language: en-US-large To: Michael Folkson , Bitcoin Protocol Discussion References: <33f275c2-06b1-4b4a-2a75-cafe36836503@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Sun, 17 Jul 2022 21:11:43 +0000 Subject: Re: [bitcoin-dev] BIP draft: Half-Aggregation of BIP-340 Signatures 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: Sun, 17 Jul 2022 20:45:36 -0000 To be clear, whether "half aggregation needs a new output type or not" does not become clear in the draft BIP because it is out of scope. Half-aggregation has a few possible applications. The draft only specifies the cryptographic scheme. The StackExchange post you link to argues that CISA requires a new output type. The same argument applies to half aggregating signatures across transaction inputs (CISHA, if you will). The only difference to "full aggregation" is that the transaction signature is a single half-aggregate signature instead of a 64-byte signature. You're right that it's possible to do batch verification of Taproot output key spends (Schnorr signatures) and script spends (key tweaks).