From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 01 Jan 2026 06:33:43 -0800 Received: from mail-ot1-f59.google.com ([209.85.210.59]) by mail.fairlystable.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1vbJkE-0002MG-Os for bitcoindev@gnusha.org; Thu, 01 Jan 2026 06:33:43 -0800 Received: by mail-ot1-f59.google.com with SMTP id 46e09a7af769-7c75290862csf23884459a34.2 for ; Thu, 01 Jan 2026 06:33:42 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1767278016; cv=pass; d=google.com; s=arc-20240605; b=GnOkE+mo7JUlwUAArfbw0VrvXlePUbD5a/hbxbiezJbJTSzQVKQ8uGjHgyjs8Alh8F 7PBZJnZnhEj/g8Sfzv+E4ImkUOpIOKCVyMpcact3WOEqPGXrq7q/viyap5/kJMax2RDw yuvmjbxweRCRN4vg91rOxHyxKE/xqy2bxlYnkwAFPoP5QwGPYF18P1X8ReB1lKALpLne GTG9RCQWxplBp6q8334t0B19svBFvqb/hjoazvtewFSq3crmwt3ycCrFlAtiCYmqSpFy Ac3NGFCjwDG5OGnGRBwhqk+rCyFsrcI+XrtoM7mV4/fn8FMgy9OeI6RVT3Pji708fanb FJhw== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:reply-to:mime-version:feedback-id :message-id:subject:from:to:date:dkim-signature; bh=FFJPoVXwouln/S/OnCqclsOP3n0xFQO4SP8jEN2eA/Y=; fh=DcxerJ1ccTA9Br4UBCCgL76558ZMizkFuQeT+T2M9ZU=; b=IIZRuB+gjtxvbiSCguw08vfce8ZyWl1wVWhGCcORLvp519S8eA8No1kK1UsY2nh/NY WCBFdP9ThNDKLF3cp+xCo8c4gares6KwqB3GQlWpHn2ZnQg78E7lrH5h5fMp3qAXnkhb tRE7SvlOVxz9N9y8JoWVBzBo9mllTu0rQgBm1A8lF7J4ReXefO12u8+SlGHKLlxRwW6M oZFU07b/jsT8cP8z0oVgH4k8Q68qHNLhfZv/U7sjw9m764lJaEjrcX15nX8ASY7Dqf3W KuahodJq57jVX/C668LtVLpghRBtLZgfwaL5PBvigV0NP8hF2g2/OQnvnOpTjC7rB5YI 0oUQ==; darn=gnusha.org ARC-Authentication-Results: i=2; gmr-mx.google.com; dkim=pass header.i=@protonmail.com header.s=protonmail3 header.b=KcIIctEO; spf=pass (google.com: domain of darosior@protonmail.com designates 185.70.43.103 as permitted sender) smtp.mailfrom=darosior@protonmail.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=protonmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=20230601; t=1767278016; x=1767882816; darn=gnusha.org; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:reply-to :x-original-authentication-results:x-original-sender:mime-version :feedback-id:message-id:subject:from:to:date:from:to:cc:subject:date :message-id:reply-to; bh=FFJPoVXwouln/S/OnCqclsOP3n0xFQO4SP8jEN2eA/Y=; b=H/pNbTWkjJcSKO6bWxNpKZgjYl/MqOOuxCvP+NsfuiYr6a/alADD/dt6+Z23g7Szg+ P9hzGzSYLPSz0OXb7UrvQ57QW1A5/VjS+tCiylMXwn8RIr1hKx8fNdi1eko+Ee5l/O7A b997FI48mJS831BWi4yG9jYgHZ7pdppdJRDDo4VaUNysFmRvGfKVGlg+v/9ZytJKsh4C DzLZPDo9tLQ/MaqGytQ1ptO/1l1v1JFMrwA0qxmcOKWrN9epcdUMSQnCDkxFjv58uEq+ hx9rvc3ENHYpvV6rqXXv6CFr5mzmHgzvTADDLuI5oe+lYRQaXkNLAY7EXohkqguwP1na j8TA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767278016; x=1767882816; h=list-unsubscribe:list-subscribe:list-archive:list-help:list-post :list-id:mailing-list:precedence:reply-to :x-original-authentication-results:x-original-sender:mime-version :feedback-id:message-id:subject:from:to:date:x-beenthere :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=FFJPoVXwouln/S/OnCqclsOP3n0xFQO4SP8jEN2eA/Y=; b=dJZJYMPxYp3z6ULdGg7FXCpE3PI9/fxbuvmpa+KO3GcnoSrrxzvS/n5erdZf+MDBPV w6cZ0C4VSLOXatpIEyHPDLCnIdDRJBfVHXZxfOyKDfsChxIf4XCEcP43NDBseUjbTM0r 3YjdeBps1FkpMuGNfb/TjGsOGxXyiB7dgZwh4mKz8A1SVUTwPCz42JEXBz7W1PaUP98d AkGmb5LgWUbQP0twOLaK4qwozazZJ0T8UDAy6vHEngNuMIRyPSWUSQDXEESyUvG7i4Kd O74719EmQ18TVxT0E25azCG3leyp5mYgEeNvXwahaLbAqZOv0px8iD/uMtMjWfUnRWDT jzlg== X-Forwarded-Encrypted: i=2; AJvYcCULEQK1/jEFdWLRcrW9RaFG0bRlnIaUkqEOi6VSxafwOBKpDe837Y+kQ+6tDZTE6rOpLUh1W4IamFcO@gnusha.org X-Gm-Message-State: AOJu0YwMGLg9tvSQCewMFpdFrctOf8IJvaLVUHED8WCGOmNnhhpOB8fn poN5qikSEGP67ooXySLZoF5YprNTeK8VNFRhALwKsA99RRyCp7DU5P+U X-Google-Smtp-Source: AGHT+IF4iBWLiR2nm+Hn3CtU0JSqFtXpOatdNau4mb3fU3Jgyp7BswiBuXTINph1sRRL8+xRbR/5xw== X-Received: by 2002:a05:6830:2692:b0:7c7:6479:38ce with SMTP id 46e09a7af769-7cc66a1a490mr20961027a34.18.1767278016122; Thu, 01 Jan 2026 06:33:36 -0800 (PST) X-BeenThere: bitcoindev@googlegroups.com; h="AWVwgWaKL7ZxdapJ/EixkujSN2NEiXoc351d2fULIytH0x3m+w==" Received: by 2002:a05:6870:548a:b0:3ea:9b4e:cb29 with SMTP id 586e51a60fabf-3fe95674220ls2418617fac.2.-pod-prod-08-us; Thu, 01 Jan 2026 06:33:31 -0800 (PST) X-Received: by 2002:a05:6808:151f:b0:44d:a3e3:40a9 with SMTP id 5614622812f47-457b1e53cbemr18697136b6e.8.1767278011416; Thu, 01 Jan 2026 06:33:31 -0800 (PST) Received: by 2002:a05:600c:5590:b0:477:b663:eee5 with SMTP id 5b1f17b1804b1-47d192350f3ms5e9; Tue, 30 Dec 2025 07:59:56 -0800 (PST) X-Received: by 2002:a05:600c:8b82:b0:47b:deb9:163d with SMTP id 5b1f17b1804b1-47d18b99b99mr367270625e9.7.1767110394359; Tue, 30 Dec 2025 07:59:54 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1767110394; cv=none; d=google.com; s=arc-20240605; b=QlouG+YfLdmrmrI7t2NqvAco6uvJlHLRnIhvcFHa1PoMl8vK0piNUiA3xYU4IuLuf+ Z0pvMDRTsrXsXE2pv7nBeOMK7rRN5RU3/PQ+e1iGitej2vfu4jivuP0e1fzefP1j+TFO slLdo7est7J0hHs6v/HU0LxXzryqJlGpM28UrFprB2TtPLKtYaIA3BHPMn58lbVtYubK 9LlUZdemPub2cvet16pWcOWct0g3WGeMJE4ATeaLYqO9YzLWwctKtmXRveOt1qG99BO2 mmzJEKVKCcWIQA4fsbSW+FrarD7qPSfTh4LB8EgGLb0BYYiP56MwhBT6I4/zxGII3LUz 3SUA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=content-transfer-encoding:mime-version:feedback-id:message-id :subject:from:to:date:dkim-signature; bh=ik2R9SZ32pU66/30IJq2XaR1QnmB3L3zwFFCJVrz0Nc=; fh=DMP0F9ULS1guKiqimntQRCN8ZraraesEgQuVcn7F0Z0=; b=P9l5YozHWdyfkanyZYCptMxpZT4amx6eGUGhmzvKwdBAccWcpECfMZ5LEPFY6K0U8O CwtXG80UjiuqLnnQzcLmTcItmrZd0XludACk4C0r6ODNMOErkUIkmDDqgIz6li5dTy0J DZpfZWXCBIYWceVkBnx/YZ3B1RNwTeskd454/gTc/Tj88WLXwaT9lskldYRfB71t9HGQ 5vGxHLKuvOcSAM5CgnGXUjIwh+vBG1t8o09JGjW+WL4thFAsYXcoG1fygEw6GbY04kNN d4m8yb8vqy4756F19jv9pgYsanuzj4Tp3T8p51qdyKIddqame9nwc7nfYFVjbiAPrvYD gbKg==; dara=google.com ARC-Authentication-Results: i=1; gmr-mx.google.com; dkim=pass header.i=@protonmail.com header.s=protonmail3 header.b=KcIIctEO; spf=pass (google.com: domain of darosior@protonmail.com designates 185.70.43.103 as permitted sender) smtp.mailfrom=darosior@protonmail.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=protonmail.com Received: from mail-43103.protonmail.ch (mail-43103.protonmail.ch. [185.70.43.103]) by gmr-mx.google.com with ESMTPS id 5b1f17b1804b1-47be3a0f840si4655285e9.1.2025.12.30.07.59.54 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Dec 2025 07:59:54 -0800 (PST) Received-SPF: pass (google.com: domain of darosior@protonmail.com designates 185.70.43.103 as permitted sender) client-ip=185.70.43.103; Date: Tue, 30 Dec 2025 15:59:49 +0000 To: Bitcoin Development Mailing List From: "'Antoine Poinsot' via Bitcoin Development Mailing List" Subject: [bitcoindev] Addressing remaining points on BIP 54 Message-ID: Feedback-ID: 7060259:user:proton X-Pm-Message-ID: bd69cc442f9e4a2030a7395026e09c3668765004 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" X-Original-Sender: darosior@protonmail.com X-Original-Authentication-Results: gmr-mx.google.com; dkim=pass header.i=@protonmail.com header.s=protonmail3 header.b=KcIIctEO; spf=pass (google.com: domain of darosior@protonmail.com designates 185.70.43.103 as permitted sender) smtp.mailfrom=darosior@protonmail.com; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=protonmail.com X-Original-From: Antoine Poinsot Reply-To: Antoine Poinsot Precedence: list Mailing-list: list bitcoindev@googlegroups.com; contact bitcoindev+owners@googlegroups.com List-ID: X-Google-Group-Id: 786775582512 List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , X-Spam-Score: -1.0 (-) Hi everyone, Some previously raised points regarding BIP 54 have come up again recently, and i would like to address them here for the record. The first one is Luke Dashjr's comment [0] that giving meaning to the coinbase transaction nLockTime is undesirable as it's the ideal position for an extranonce. But this extranonce only enables a theoretical optimisation for a non-bottleneck operation: saving an ASIC controller one SHA256 of the coinbase transaction. Besides, committing to block height in nLockTime is the most elegant way to guarantee coinbase transaction uniqueness without relying on non-portable BIP 30 validation. The field is intended for this purpose and timelock validation neatly guarantees historical uniqueness. Furthermore, it makes it possible to extract the block height from the coinbase transaction without having to parse Script, and enables constant-time proofs of block height [1]. The second one is Jeremy Rubin's comment [2] that we may want to keep 64-byte transactions, that the validity "seam" this introduces may bring unforeseen complexity [3] in the design of smart contracts, and that it might be preferable to introduce a whole new (sparse) Merkle tree instead. But as long as Bitcoin remains remotely similar to today, any transaction that does not burn funds will serialize as more than 64 witness-stripped bytes. This is valid regardless of where the transaction is crafted. Not burning funds is already a concern when designing smart contracts: as long as this is covered, invalidating 64-byte transactions does not introduce an additional edge case. Moreover, the sparse Merkle tree suggestion would be a major change to a core protocol component, with far-reaching implications. Such a "soft" fork would blind unupgraded nodes, not only to others' transaction signatures like with Segwit, but to the entirety of the transaction traffic. This is not the right tradeoff. I certainly agree that introducing an explicit restriction on a specific transaction size is inelegant, and i'm partial to arguments about unforeseen complexity. But when the alternatives are leaving a notorious footgun to upper-layer developers [4], or making a far more invasive change that effectively mandates an extension block, this is pragmatically the least bad solution. Antoine Poinsot [0]: Initially raised on the PR to the BIPs repository, but the latest iteration is in response to my recent email to the Bitcoin mining development mailing list. See here https://groups.google.com/g/bitcoinminingdev/c/jlqlNHHNSNk/m/RBT_LBWQAgAJ and the thread thereafter. [1]: https://delvingbitcoin.org/t/great-consensus-cleanup-revival/710/26 [2]: To the best of my knowledge, Jeremy has not published a description of his proposal. So i'm basing my response on this interview: https://youtu.be/FNKipXl5DTY?t=769. [3]: An argument previously raised by Eric Voskuil and weighed in the Consensus Cleanup's Delving thread. See this comment for an attempt at summarizing the discussion up to that point: https://delvingbitcoin.org/t/great-consensus-cleanup-revival/710/41 [4]: Even the BitVM bridge developers overlooked the need for implementing a mitigation for this (https://github.com/BitVM/BitVM/issues/285). -- You received this message because you are subscribed to the Google Groups "Bitcoin Development Mailing List" group. To unsubscribe from this group and stop receiving emails from it, send an email to bitcoindev+unsubscribe@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/bitcoindev/UsKuvCXXhSAnNVx5a0K2UfP3srAr3slW9mcOjtYk9LnolaOXfWrW9jpqbxsQQPkyQuZogkhz2Hbfwii2VsTm79vRDpgKduxk35hpBu_t7Do%3D%40protonmail.com.