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
|
Return-Path: <jl2012@xbt.hk>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id A133D954
for <bitcoin-dev@lists.linuxfoundation.org>;
Wed, 8 Jun 2016 08:24:20 +0000 (UTC)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from s37.web-hosting.com (s37.web-hosting.com [198.54.114.154])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 23356129
for <bitcoin-dev@lists.linuxfoundation.org>;
Wed, 8 Jun 2016 08:24:20 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xbt.hk;
s=default;
h=To:References:Message-Id:Cc:Date:In-Reply-To:From:Content-Type:
Mime-Version:Subject; bh=TSv2Huq8eYRV2KNE0sEAVNA7ds7f6fDVOYnOdE5sR04=;
b=Fqrx
Bju/ecpr6b1Uu6Uk88u/o0kBt94bII0rjFU2JD5FX5stpKEBqn6Wi1xtK1K0ulLZKHfkP5EytR21v
vthhXdtgKf4AmluQorU+PkssGdt8n2fA57Eefor8FLjUab9txSADfbnMuXhCppY08kkmjTZv06Vh2
wub33gL1A+7akRVXC2tHAR/UG3YseGWJdk4AQrWzjB6hvcho+bfrcZD78C9JKXFoIAezZlhAmp4zJ
K5XtKKT0TRVxXKTkn8rpS7jwmigAcvwPUpBzWz9VrsvtSvOqr1cfQo9BpPMRIPBdYftD5RE9AmUA5
0FK8CgHNyjjfPIKGOTgCrJp36NVLlQ==;
Received: from [137.189.134.42] (port=60194 helo=[192.168.0.102])
by server37.web-hosting.com with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256)
(Exim 4.86_1) (envelope-from <jl2012@xbt.hk>)
id 1bAYmg-001QxD-HS; Wed, 08 Jun 2016 04:24:18 -0400
Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\))
Content-Type: multipart/signed;
boundary="Apple-Mail=_B154EDAD-2DFC-44B9-B519-0A591083CD19";
protocol="application/pgp-signature"; micalg=pgp-sha512
X-Pgp-Agent: GPGMail 2.6b2
From: Johnson Lau <jl2012@xbt.hk>
In-Reply-To: <201606080729.24789.luke@dashjr.org>
Date: Wed, 8 Jun 2016 16:23:51 +0800
Message-Id: <D192E876-1A4F-4B06-86F6-54F1BDEC857D@xbt.hk>
References: <A7E9BC23-6860-4B31-9D4E-11F771A5E581@xbt.hk>
<201606080729.24789.luke@dashjr.org>
To: Luke Dashjr <luke@dashjr.org>
X-Mailer: Apple Mail (2.3124)
X-AntiAbuse: This header was added to track abuse,
please include it with any abuse report
X-AntiAbuse: Primary Hostname - server37.web-hosting.com
X-AntiAbuse: Original Domain - lists.linuxfoundation.org
X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12]
X-AntiAbuse: Sender Address Domain - xbt.hk
X-Get-Message-Sender-Via: server37.web-hosting.com: authenticated_id:
jl2012@xbt.hk
X-Authenticated-Sender: server37.web-hosting.com: jl2012@xbt.hk
X-Source:
X-Source-Args:
X-Source-Dir:
X-From-Rewrite: unmodified, already matched
X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
T_DKIM_INVALID autolearn=no version=3.3.1
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
smtp1.linux-foundation.org
Cc: bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] BIP141 segwit consensus rule update: extension of
witness program definition
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.12
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: Wed, 08 Jun 2016 08:24:20 -0000
--Apple-Mail=_B154EDAD-2DFC-44B9-B519-0A591083CD19
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain;
charset=utf-8
> On 8 Jun 2016, at 15:29, Luke Dashjr <luke@dashjr.org> wrote:
>=20
> On Wednesday, June 08, 2016 5:57:36 AM Johnson Lau via bitcoin-dev =
wrote:
>> Why not make it even bigger, e.g. 75 bytes?
>=20
> I don't see a sufficient answer to this question. Pieter explained why =
>75
> would be annoying, but 75 seems like it should be fine.
>=20
>> In any case, since scripts with a 1-byte push followed by a push of =
>40
>> bytes remain anyone-can-spend, we always have the option to redefine =
them
>> with a softfork.
>=20
> It's not that simple, since this is preventing use of the witness =
field for
> such scripts. With this limit in place, any such a softfork would =
suddenly
> require either two different witness commitments, or disabling the =
previous
> witness transaction format.
>=20
> Luke
This is exactly why I proposed to extend the definition. My initial =
proposal was extending it to 33 bytes to effectively allow 16*256 new =
script versions, assuming we will keep using 32 bytes program hash.
If someday 32 bytes hash is deemed to be unsafe, the txid would also be =
unsafe and a hard fork might be needed. Therefore, I don=E2=80=99t see =
how a witness program larger than 40 bytes would be useful in any case =
(as it is more expensive and takes more UTXO space). I think Pieter =
doesn=E2=80=99t want to make it unnecessarily lenient.
--Apple-Mail=_B154EDAD-2DFC-44B9-B519-0A591083CD19
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
filename=signature.asc
Content-Type: application/pgp-signature;
name=signature.asc
Content-Description: Message signed with OpenPGP using GPGMail
-----BEGIN PGP SIGNATURE-----
Comment: GPGTools - https://gpgtools.org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=XUsg
-----END PGP SIGNATURE-----
--Apple-Mail=_B154EDAD-2DFC-44B9-B519-0A591083CD19--
|
