1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
Return-Path: <pete@petertodd.org>
Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133])
by lists.linuxfoundation.org (Postfix) with ESMTP id 30E25C002B
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 7 Feb 2023 12:50:20 +0000 (UTC)
Received: from localhost (localhost [127.0.0.1])
by smtp2.osuosl.org (Postfix) with ESMTP id F2D1A40516
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 7 Feb 2023 12:50:19 +0000 (UTC)
DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org F2D1A40516
Authentication-Results: smtp2.osuosl.org; dkim=pass (2048-bit key,
unprotected) header.d=messagingengine.com header.i=@messagingengine.com
header.a=rsa-sha256 header.s=fm3 header.b=BUIlm+a6
X-Virus-Scanned: amavisd-new at osuosl.org
X-Spam-Flag: NO
X-Spam-Score: -2.602
X-Spam-Level:
X-Spam-Status: No, score=-2.602 tagged_above=-999 required=5
tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1,
RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001]
autolearn=ham autolearn_force=no
Received: from smtp2.osuosl.org ([127.0.0.1])
by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)
with ESMTP id Y78yFaQYTpby
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 7 Feb 2023 12:50:18 +0000 (UTC)
X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0
DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 9317540232
Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com
[64.147.123.20])
by smtp2.osuosl.org (Postfix) with ESMTPS id 9317540232
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 7 Feb 2023 12:50:18 +0000 (UTC)
Received: from compute5.internal (compute5.nyi.internal [10.202.2.45])
by mailout.west.internal (Postfix) with ESMTP id 8CC283200903;
Tue, 7 Feb 2023 07:50:16 -0500 (EST)
Received: from mailfrontend2 ([10.202.2.163])
by compute5.internal (MEProxy); Tue, 07 Feb 2023 07:50:16 -0500
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=
messagingengine.com; h=cc:cc:content-type:date:date:feedback-id
:feedback-id:from:from:in-reply-to:in-reply-to:message-id
:mime-version:references:reply-to:sender:subject:subject:to:to
:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=
fm3; t=1675774216; x=1675860616; bh=CrlSBVHlovy7gLEhOdbLaecT1V9e
EwXZCCxmTmAQktI=; b=BUIlm+a653mvUHk58ecPegIcTDqUv7Vex3Sg5sKNSEPQ
QIHHFwK518SXRZwHJLgJVt3NY+xIugNuQg+o0Ex1svapNBgjlxy7GEVFg/PQIOFG
UJo6odlB203wOa/iTKetFc4hKZujQKfgnZz9wM6F0Qg0s2tabe7K+l5NA3p3F89a
vUN0+yWPaJLpKu2cFMBSFXbjNBe///FhmyhaO99oMHr1S80HrR01vVzS6uY1N+C5
u/Po9bMFE5PKaP4p1y9tN8dqKQpERmFW+obLSaJa2jaXZv6bnhz+r5s+71AXMOHc
dmTvU4Rjn0z2lICGIaxv7W8Hq410e7UwM/gMFPVAkg==
X-ME-Sender: <xms:B0niY_fQXDNk0OEhFSx7IHJuhTGXRuCioMRDvmvPX7I2PvXd-mYjhg>
<xme:B0niY1P_7F_KfadDm6DMParNBAm6_SRYA78zJcRVR2wcmPw053GpHygm1Lxbf-kZP
ME_eHlKjGi-LUJWl9g>
X-ME-Received: <xmr:B0niY4igMRentMm6NnnGVj10aJuoBdZ0tw_DCzV95oc0F_jcOb5LJIE1hQ>
X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrudegkedggedvucetufdoteggodetrfdotf
fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen
uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne
cujfgurhepfffhvfevuffkfhggtggujgesghdtreertddtvdenucfhrhhomheprfgvthgv
rhcuvfhougguuceophgvthgvsehpvghtvghrthhouggurdhorhhgqeenucggtffrrghtth
gvrhhnpeelvdellefftddukeduffejgfefjeeuheeileeftdfgteduteeggeevueethfej
tdenucffohhmrghinhepphgvthgvrhhtohguugdrohhrghenucevlhhushhtvghrufhiii
gvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehpvghtvgesphgvthgvrhhtohguugdr
ohhrgh
X-ME-Proxy: <xmx:B0niYw_2nqhTwn0GvsJUj2-Z5MVXoFtG4vIvWCyT7ZRmwbF9M75Dig>
<xmx:B0niY7sC2LBFf-Fm7JomXWIpcrESMvnhlpxmHC3VHiwveRmcOgsBAg>
<xmx:B0niY_HHt43hPig6msV2wlXoJDSZzbVx4W0K3srFOX18PhyKcyvrYg>
<xmx:CEniY1KpsHiFgkn1F8K6S6D-i2L-7BmyX1-Nyt38XhWVJeeJ37TAWA>
Feedback-ID: i525146e8:Fastmail
Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue,
7 Feb 2023 07:50:15 -0500 (EST)
Received: by localhost (Postfix, from userid 1000)
id 421445F824; Tue, 7 Feb 2023 07:50:13 -0500 (EST)
Date: Tue, 7 Feb 2023 07:50:13 -0500
From: Peter Todd <pete@petertodd.org>
To: Nadav Ivgi <nadav@shesek.info>,
Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Message-ID: <Y+JJBXsgJGSRZR29@petertodd.org>
References: <CAAQdECCH=YOcu4g6Ku1_G4CnRg6rsaFPFPwbABx9aZin9A8+2A@mail.gmail.com>
<CAGXD5f3Bu3+BsbRQNcA=eugW7FDdgR0xQdpn66925b4DjRyJeQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
protocol="application/pgp-signature"; boundary="MANY8PoWM0q8mSt7"
Content-Disposition: inline
In-Reply-To: <CAGXD5f3Bu3+BsbRQNcA=eugW7FDdgR0xQdpn66925b4DjRyJeQ@mail.gmail.com>
Subject: Re: [bitcoin-dev] Unenforceable fee obligations in multiparty
protocols with Taproot inputs
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Bitcoin Protocol Discussion <bitcoin-dev.lists.linuxfoundation.org>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/bitcoin-dev>,
<mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/>
List-Post: <mailto:bitcoin-dev@lists.linuxfoundation.org>
List-Help: <mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev>,
<mailto:bitcoin-dev-request@lists.linuxfoundation.org?subject=subscribe>
X-List-Received-Date: Tue, 07 Feb 2023 12:50:20 -0000
--MANY8PoWM0q8mSt7
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Tue, Feb 07, 2023 at 11:36:58AM +0200, Nadav Ivgi via bitcoin-dev wrote:
> > Since Taproot (more generally any kind of MAST) spends have variable si=
ze
>=20
> Isn't this the case with any arbitrary script execution? Non-taproot
This is even been true for P2PKH inputs: you can double the space of your
scriptSigs by using uncompressed pubkeys instead of compressed pubkeys.
> If the goal is to only allow registering simple singlesig-encumbered UTXOs
> like P2(W)PKH, the participants could be asked to prove that their P2TR
> output commits to an unspendable script path [0].
Technically, only the last person to sign needs to prove this in advance.
Everyone else can prove it with their signatures.
This distinction could be useful to support coinjoin participants spending
complex P2TR outputs into coinjoins, a perfectly valid use-case in theory so
long as they're paying appropriate fees. Though due to how difficult it is =
to
validate scripts reliably outside the consensus code base, allowing this for
arbitrary scripts could lead to DoS attacks where someone takes advantage o=
f a
bug in script execution to create an invalid transaction.
--=20
https://petertodd.org 'peter'[:-1]@petertodd.org
--MANY8PoWM0q8mSt7
Content-Type: application/pgp-signature; name="signature.asc"
-----BEGIN PGP SIGNATURE-----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=Be1P
-----END PGP SIGNATURE-----
--MANY8PoWM0q8mSt7--
|
