From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id A3DD8C000E; Tue, 10 Aug 2021 06:15:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 93F3960620; Tue, 10 Aug 2021 06:15:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -1.725 X-Spam-Level: X-Spam-Status: No, score=-1.725 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, RCVD_IN_XBL=0.375, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=no autolearn_force=no Authentication-Results: smtp3.osuosl.org (amavisd-new); dkim=pass (1024-bit key) header.d=dtrt.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 96bDs3U9SSN5; Tue, 10 Aug 2021 06:15:34 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from newmail.dtrt.org (newmail.dtrt.org [IPv6:2600:3c03::f03c:91ff:fe7b:78d1]) by smtp3.osuosl.org (Postfix) with ESMTPS id 66E2F6063A; Tue, 10 Aug 2021 06:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=dtrt.org; s=20201208; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=fjmv4GIB3MCaFuG+5qDN9hZkaJpPMAlHyZuBtFJMyyI=; b=ap6PSi55mh8CbuDnXlIRXb45pU +qIDpagIHs/2OzjaZafC/79RHxjNdzY8HicSXh3DE2qZ9+atxdcGQAU2+rV3nyALKtEKDzd+DRCkO A5M7cbJMvlE7u+FJaEYvofoeBKRkwn7A3uuSDkfeRh+321ImSJbpEAgw99vT50lvmJow=; Received: from harding by newmail.dtrt.org with local (Exim 4.92) (envelope-from ) id 1mDL2x-0008Df-89; Mon, 09 Aug 2021 20:15:31 -1000 Date: Mon, 9 Aug 2021 20:14:41 -1000 From: "David A. Harding" To: Antoine Riard Message-ID: <20210810061441.6rg3quotiycomcp6@ganymede> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="jnefyx4fdpdtq5cx" Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Cc: Bitcoin development mailing list , lightning-dev Subject: Re: [bitcoin-dev] [Lightning-dev] Removing the Dust Limit 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: Tue, 10 Aug 2021 06:15:38 -0000 --jnefyx4fdpdtq5cx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 09, 2021 at 09:22:28AM -0400, Antoine Riard wrote: > I'm pretty conservative about increasing the standard dust limit in any > way. This would convert a higher percentage of LN channels capacity into > dust, which is coming with a lowering of funds safety [0].=20 I think that reasoning is incomplete. There are two related things here: - **Uneconomical outputs:** outputs that would cost more to spend than the value they contain. - **Dust limit:** an output amount below which Bitcoin Core (and other nodes) will not relay the transaction containing that output. Although raising the dust limit can have the effect you describe,=20 increases in the minimum necessary feerate to get a transaction confirmed in an appropriate amount of time also "converts a higher percentage of LN channel capacity into dust". As developers, we have no control over prevailing feerates, so this is a problem LN needs to deal with regardless of Bitcoin Core's dust limit. (Related to your linked thread, that seems to be about the risk of "burning funds" by paying them to a miner who may be a party to the attack. There's plenty of other alternative ways to burn funds that can change the risk profile.) > the standard dust limit [...] introduces a trust vector=20 My point above is that any trust vector is introduced not by the dust limit but by the economics of outputs being worth less than they cost to spend. > LN node operators might be willingly to compensate this "dust" trust vect= or > by relying on side-trust model They could also use trustless probabalistic payments, which have been discussed in the context of LN for handling the problem of payments too small to be represented onchain since early 2016: https://docs.google.com/presentation/d/1G4xchDGcO37DJ2lPC_XYyZIUkJc2khnLrCa= ZXgvDN0U/edit?pref=3D2&pli=3D1#slide=3Did.g85f425098_0_178 (Probabalistic payments were discussed in the general context of Bitcoin well before LN was proposed, and Elements even includes an opcode for creating them.) > smarter engineering such as utreexo on the base-layer side=20 Utreexo doesn't solve this problem. Many nodes (such as miners) will still want to store the full UTXO set and access it quickly, Utreexo proofs will grow in size with UTXO set size (though, at best, only log(n)), so full node operators will still not want their bandwidth wasted by people who create UTXOs they have no reason to spend. > I think the status quo is good enough for now I agree. -Dave --jnefyx4fdpdtq5cx Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEgxUkqkMp0LnoXjCr2dtBqWwiadMFAmESGVEACgkQ2dtBqWwi adMaow/+LTG4J3VJ4zniZ09cQOtla728pKpELzBwSk1RCeBMVaLuWg4RmZiIKFuw PoH/wOGBzkoxCCmxDY3BIjWbOODfB0Ah8GaxDbDsbIjhxJ6XnPJrMC388APP0TML SSyLqleUt1RPJ6Ya4iRkVJpAs3iTk2+UgAXFNqFzi/z0fiLXo+xmeEUnmT0t+0kS KuGRbnhK3G4zV+PsMUQzmO6qriP7tTHamRzGBYVyPC92VyfibZyUhfvlN1k+GPSl jXwOlvUoQrQwVnnMz2fTutGmAvMIZEA3XLaWO3Y+P1dNGMObpe5x4afy8uBplerR 3hVfVvwU4JbsU+eaS+6cKzFX98e8mco7UvugABDcNbK4NXW8udiC/zD1qFZsa31Z 5tYjtc9fkWm2zT7lgCZYOzyp/8SU8NJ2rb9+VhdMslxTj4rXwkq7E4okHRWlaERQ x850Z7AJfaD2mAdbFd6OgXo+frv+UiumwuElumK8vxRVfTIkXK+FCwt7v8DeHwVW 6nkWt67vlPzJEHsS54ng9MIKen6dUx8c+OHI8sR81SzcFdHEXS1Khx9+X8F6sCGh 2TpLFiqE8yIg72EEhBm07UygV91NEzc8IELIZgigPn7ci4/6CbwK7ZoNEnqrDVOh UGGem7a7zSDo5bYpwrBAYZ/bzg4FU+os1IKcVrqwkR7ddqnCEJY= =FNKU -----END PGP SIGNATURE----- --jnefyx4fdpdtq5cx--