From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id CE892C0032 for ; Thu, 26 Oct 2023 16:05:06 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id A6B4E8193E for ; Thu, 26 Oct 2023 16:05:06 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org A6B4E8193E Authentication-Results: smtp1.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20230601 header.b=Rk8ggdkn X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.098 X-Spam-Level: X-Spam-Status: No, score=-2.098 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, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id E9B1TxD2_YSi for ; Thu, 26 Oct 2023 16:05:05 +0000 (UTC) Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) by smtp1.osuosl.org (Postfix) with ESMTPS id 8AB4B819BC for ; Thu, 26 Oct 2023 16:05:05 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 8AB4B819BC Received: by mail-ot1-x334.google.com with SMTP id 46e09a7af769-6cd0963c61cso689649a34.0 for ; Thu, 26 Oct 2023 09:05:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1698336304; x=1698941104; darn=lists.linuxfoundation.org; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :from:to:cc:subject:date:message-id:reply-to; bh=U+2WNMAz5wQYdhpfjyIbHCH7DULrhFPswtHGap4pE1Q=; b=Rk8ggdknpi2xdcXwzmJxcryJjk409ajI3XHMgYkL2JsUSWegsNkF3pImonbDn/Sb/F 0KySoy6gqnaYwqHJbJMpXLL11TSlhilwYsyqe++KAnmsL6hRhcbNWme0gQ2NoE7x3tNS XNMWqTdhsVyUk3TTHg2+noFLkWYMZgljej2uKaWQt99PozzGVsGXibVB8VhOp5nLGzca YTjPa6pkYUQi5mMAeGNRxjry3Y+ot1v7e+ScjQ+0PAZnkXVAi2fw1zAV9WRQIPGw1ZY5 HGZFuyzKLayjY21tSIpJmfXg3JKg6X5nva+qR3eaT0UcMVf1yLkahyxCso9JAUZfErlK Qw4g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698336304; x=1698941104; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=U+2WNMAz5wQYdhpfjyIbHCH7DULrhFPswtHGap4pE1Q=; b=h6ZY/29QRzAEGhu/Y9oKUF8vSuHku7qzHxxEjXgrIzE4NDsxujCsfdj2dGz736b7oG Hu79TpgH4ff9+pfVHzBG0IuWxLFv3GNreg28LZlduJF9e+Bv82HVfpj/jO6d/GtTqz+B 2xqYJtoPnPT95ZTtCTBJfzlMD467WZZ+snk+tS2Yo3UtG5ZHM82YP48i15vZ3Ssht4Pz 0qrxaGShmfExJKvVYjxq1Ojf9gqrNkAT2ZsJV/S6dzjq72BPubtMB1itGFxsDO8EOtor WjSEJoPn4yDkr1Uh/sXPQMoyDcPRUjb2Q53EwbISxt7KfE+8UkJdi2vtHkQ3iVE348v6 SNqQ== X-Gm-Message-State: AOJu0YyAEAlUvhMbh+YLfSZsrxuWjr6TNxoKDIhdKH2ZpUFCtAt88SYE r6vjZDp3WrJYOQD8mSkyZECqCojZRUMuvUYhQtopdzagMZ/xPg== X-Google-Smtp-Source: AGHT+IH9Jr1OcOjHm0b1cS9N9Z92glXUy/j0EYYvKTFXTZJK9rwMY1LFzF9pUIjHaolC1+80H5QfDoM38FjAVYAVfs0= X-Received: by 2002:a05:6870:9689:b0:1ea:323e:4f13 with SMTP id o9-20020a056870968900b001ea323e4f13mr18474490oaq.20.1698336304304; Thu, 26 Oct 2023 09:05:04 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: "James O'Beirne" Date: Thu, 26 Oct 2023 12:04:52 -0400 Message-ID: To: Andrew Poelstra , Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary="0000000000002096c30608a0bc44" X-Mailman-Approved-At: Thu, 26 Oct 2023 19:27:57 +0000 Subject: Re: [bitcoin-dev] Proposed BIP for OP_CAT 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, 26 Oct 2023 16:05:06 -0000 --0000000000002096c30608a0bc44 Content-Type: text/plain; charset="UTF-8" I have to admit - I'm somewhat baffled at the enthusiasm for a "just CAT" softfork, since I can't see that it would achieve much. It's indicative to me that there isn't a compelling example to date that (i) actually has working code and (ii) only relies upon CAT. I'm not averse to CAT, just confused that there's a lot of enthusiasm for a CAT-only fork. To do actually-interesting covenants, afacit you'd need "introspection" opcodes and/or CHECKSIGFROMSTACK - and even then, for almost all applications I'm familiar with, that kind of CAT-based approach would be much more circuitous than the alternatives that have been discussed for years on this list. > Vaults I don't think this is actually a use-case that CAT materially helps with. Andrew's posts, while well written and certainly foundational, do not sketch a design for vaults that someone would actually use. I don't see how CAT alone (without many auxiliary introspection opcodes) facilitates vaults that clear the usability hurdles I describe in this paper: https://jameso.be/vaults.pdf. For example, batched withdrawals and partial unvaultings don't seem possible. Even with introspection opcodes, Burak's ( https://brqgoo.medium.com/emulating-op-vault-with-elements-opcodes-bdc7d8b0fe71) prototype wasn't able to handle revaulting - an important feature for usability (https://twitter.com/jamesob/status/1636546085186412544). > Tree signatures To what extent does Taproot obviate this use? --0000000000002096c30608a0bc44 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I have to admit - I'm somewhat baffled at the ent= husiasm for a "just CAT" softfork, since I can't see that it = would achieve much. It's indicative to me that there isn't a compel= ling example to date that (i) actually has working code and (ii) only relie= s upon CAT. I'm not averse to CAT, just confused that there's a lot= of enthusiasm for a CAT-only fork.

To do actu= ally-interesting covenants, afacit you'd need "introspection"= opcodes and/or CHECKSIGFROMSTACK - and even then, for almost all applicati= ons I'm familiar with, that kind of CAT-based approach would be much mo= re circuitous than the alternatives that have been discussed for years on t= his list.

> Vaults

I d= on't think this is actually a use-case that CAT materially helps with. = Andrew's posts, while well written and certainly foundational, do not s= ketch a design for vaults that someone would actually use. I don't see = how CAT alone (without many auxiliary introspection opcodes) facilitates va= ults that clear the usability hurdles I describe in this paper: https://jameso.be/vaults.pdf. For example= , batched withdrawals and partial unvaultings don't seem possible.=C2= =A0

Even with introspection opcodes, Burak's (= https://brqgoo.medium.com/emulating-op-vault-with-elements= -opcodes-bdc7d8b0fe71) prototype wasn't able to handle revaulting -= an important feature for usability (https://twitter.com/jamesob/status/16365460851= 86412544).

> Tree signatures

=
To what extent does Taproot obviate this use?
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