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[202.12.124.148]) by gmr-mx.google.com with ESMTPS id af79cd13be357-7d3f9a20296si5960785a.3.2025.06.20.07.28.36 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 20 Jun 2025 07:28:36 -0700 (PDT) Received-SPF: pass (google.com: domain of pete@petertodd.org designates 202.12.124.148 as permitted sender) client-ip=202.12.124.148; Received: from phl-compute-06.internal (phl-compute-06.phl.internal [10.202.2.46]) by mailfout.stl.internal (Postfix) with ESMTP id A4B761140260; Fri, 20 Jun 2025 10:28:35 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-06.internal (MEProxy); Fri, 20 Jun 2025 10:28:35 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtddvgdekieegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceurghi lhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurh epfffhvfevuffkfhggtggujgesghdtroertddtvdenucfhrhhomheprfgvthgvrhcuvfho ugguuceophgvthgvsehpvghtvghrthhouggurdhorhhgqeenucggtffrrghtthgvrhhnpe ffgfejudffledtveelheekkeegleeukeelteetieekgfekjefgjeehtddvledtvdenucff ohhmrghinhepgidrtghomhdpghhithhhuhgsrdgtohhmpdhpvghtvghrthhouggurdhorh hgnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepphgv thgvsehpvghtvghrthhouggurdhorhhgpdhnsggprhgtphhtthhopeefpdhmohguvgepsh hmthhpohhuthdprhgtphhtthhopehgshgrnhguvghrshekjeesghhmrghilhdrtghomhdp rhgtphhtthhopehjrghmvghsrdhosggvihhrnhgvsehgmhgrihhlrdgtohhmpdhrtghpth htohepsghithgtohhinhguvghvsehgohhoghhlvghgrhhouhhpshdrtghomh X-ME-Proxy: Feedback-ID: i525146e8:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 20 Jun 2025 10:28:35 -0400 (EDT) Received: by localhost (Postfix, from userid 1000) id 19CE39FBE0; Fri, 20 Jun 2025 14:28:28 +0000 (UTC) Date: Fri, 20 Jun 2025 14:28:28 +0000 From: Peter Todd To: Greg Sanders Cc: James O'Beirne , Bitcoin Development Mailing List Subject: Re: [bitcoindev] CTV + CSFS: a letter Message-ID: References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="krG4T+Fn4Ucf7yWB" Content-Disposition: inline In-Reply-To: X-Original-Sender: pete@petertodd.org X-Original-Authentication-Results: gmr-mx.google.com; dkim=pass header.i=@messagingengine.com header.s=fm1 header.b=SgM4ycGs; spf=pass (google.com: domain of pete@petertodd.org designates 202.12.124.148 as permitted sender) smtp.mailfrom=pete@petertodd.org 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: -0.8 (/) --krG4T+Fn4Ucf7yWB Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline On Wed, Jun 11, 2025 at 11:33:35AM -0400, Greg Sanders wrote: > It clearly can be a liability if the relative utility of CTV is damaged by > a possible future change, even non-consensus ones, some of which are > already being deployed with non-zero miner support such as > https://x.com/PortlandHODL/status/1921350395424563572 . This could have led > to legitimate usage of CTV being trivially DoS'able. Good news is there are > practical if not beautiful mitigations to this that don't involve annex > commitment. See https://github.com/bitcoin/bitcoin/pull/32453 and > https://github.com/petertodd/bitcoin/pull/10 for some relevant details. Note that in this example the "mitigation" is simply enforcing what is optimal for miners: mining annexes only when the annexes are required for the transaction to be valid. A miner who had allowed standard annexes who was *not* mining CTV transactions because of a large uncommitted annex is just unnecessarily losing money. They could easily take that exact transaction, remove the uncommitted annex, and earn a bit more money. In much the same way that a miner can always do themselves unnecessary harm by disabling the clean-stack check, and then failing to mine perfectly valid transactions that would be more profitable if the extraneous stack elements were removed (modulo non-segwit cases with high-fee child transactions of course). It may be a good idea for CTV to commit to annexes. But this issue isn't a reason to do so. -- https://petertodd.org 'peter'[:-1]@petertodd.org -- 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/aFVwDLBUJBbHKJLX%40petertodd.org. --krG4T+Fn4Ucf7yWB Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE0RcYcKRzsEwFZ3N5Lly11TVRLzcFAmhVcA4ACgkQLly11TVR LzferQ/+PFiMFOLNFCycIQ0Wd1n2YGGW6YUTBVkk1J0T1tjiwZVOwHK/RsALsVmT ZaEtvBPP8cWLQSaYezNGUF2VzWUjoiM7zbjUx0hwMG8NhFnxSrJ6QAdn0icqXxLf l8v6Cx6sOoYZ+sYUVAnQsGDpZ58/b7nrwE60lkXYAS2X1x+owqvWll11CULBEecv 4qGi0w6qtm/nyPl8UdTT9li0bGxlXl5W5uCCncpvU6T2VKeQuccMLQQN8bIzFvRe DcUEy9YTc3uUpZGhzHXt9LvW1NWvP/09aGP4XETwQOm3km+JFzsigjJjZuNceFxq osha/wj2jndTGCXubYNPIfYvL/PpYf3AaIm94LV8eIuXwGb9vzQ9fDHLS9FYNoFj CJopGRYIR9k+ijqYJL25VI1pZ2i+E2UVTpDjAq2sXIaZbh3IGzoWNNeziWiSL2oF 0LvYP1e5Xr9r9nqQRs3c3qgvoR0g+ZKkksrM8jsgXR5uI79N2lwVSI0e4FX0gxCY sh6Pg+mT8NSV87lAoIYSfodKrdBLjmfIgv15OwE6N3cjD9j9bpr+LHWI92glPhzX sLUF0zFwJpC2/Ac2JoFpEPfEpZX6V9cwwPtTxR4gCvcg1z6fPmknuJfcN6WNVKJ2 MiPRCgJpfu+l8/aEgg4pRW+kTnGrnxpJMjd/5Ev22cjxPyKXD2c= =li4V -----END PGP SIGNATURE----- --krG4T+Fn4Ucf7yWB--