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
|
Return-Path: <pete@petertodd.org>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id C99C9C91
for <bitcoin-dev@lists.linuxfoundation.org>;
Sun, 20 Dec 2015 11:25:03 +0000 (UTC)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.6
Received: from outmail149113.authsmtp.com (outmail149113.authsmtp.com
[62.13.149.113])
by smtp1.linuxfoundation.org (Postfix) with ESMTP id A4BC9A0
for <bitcoin-dev@lists.linuxfoundation.org>;
Sun, 20 Dec 2015 11:25:02 +0000 (UTC)
Received: from mail-c232.authsmtp.com (mail-c232.authsmtp.com [62.13.128.232])
by punt21.authsmtp.com (8.14.2/8.14.2/) with ESMTP id tBKBP1Kc081036;
Sun, 20 Dec 2015 11:25:01 GMT
Received: from muck ([24.114.39.101]) (authenticated bits=128)
by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id tBKBOt1k075970
(version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO);
Sun, 20 Dec 2015 11:24:59 GMT
Date: Sun, 20 Dec 2015 03:24:54 -0800
From: Peter Todd <pete@petertodd.org>
To: Gregory Maxwell <greg@xiph.org>
Message-ID: <20151220112454.GB16187@muck>
References: <50e629572d8de852eb789d50b34da308@xbt.hk>
<1449961269.2210.5.camel@yahoo.com>
<CACrzPenXGQZBrx8QC+1QE2oCE3N=qmfgc_OWrowtjtLjGkZrRA@mail.gmail.com>
<CAAS2fgQi7aiwyOaVBiMbp6t9D58aFAmDdKPzFiscB6ouGzBK6A@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;
protocol="application/pgp-signature"; boundary="TakKZr9L6Hm6aLOc"
Content-Disposition: inline
In-Reply-To: <CAAS2fgQi7aiwyOaVBiMbp6t9D58aFAmDdKPzFiscB6ouGzBK6A@mail.gmail.com>
X-Server-Quench: 4ee93efb-a70c-11e5-829e-00151795d556
X-AuthReport-Spam: If SPAM / abuse - report it at:
http://www.authsmtp.com/abuse
X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVKBZePFsRUQkR
aQdMdAIUHFAXAgsB AmMbWlVeUlh7WWI7 aQ5PbARZfElHQQRq
UVdMSlVNFUssc2dz eVofCRl1cgxBeDBx Z0RjWD5fCRFzdhMr
EFMFEm1VeGZhPWUC WEJRIh5UcAJPfxhM bwR6UXVDAzANdhEy
HhM4ODE3eDlSNhEd bAYXIl8OCUoMBDs1 QQxKIAkfOlZNWCQv
Lxs7NhYXG0AfM145 OEcgX11QOR4OAQpf GSkA
X-Authentic-SMTP: 61633532353630.1037:706
X-AuthFastPath: 0 (Was 255)
X-AuthSMTP-Origin: 24.114.39.101/587
X-AuthVirus-Status: No virus detected - but ensure you scan with your own
anti-virus system.
X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW
autolearn=ham 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] Forget dormant UTXOs without confiscating bitcoin
X-BeenThere: bitcoin-dev@lists.linuxfoundation.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Bitcoin Development 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: Sun, 20 Dec 2015 11:25:03 -0000
--TakKZr9L6Hm6aLOc
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Sun, Dec 13, 2015 at 02:07:36AM +0000, Gregory Maxwell via bitcoin-dev w=
rote:
> On Sun, Dec 13, 2015 at 1:00 AM, Vincent Truong via bitcoin-dev
> <bitcoin-dev@lists.linuxfoundation.org> wrote:
> > have run a node/kept their utxo before they were aware of this change a=
nd
> > then realise miners have discarded their utxo. Oops?
>=20
> I believe you have misunderstood jl2012's post. His post does not
> cause the outputs to become discarded. They are still spendable,
> but the transactions must carry a membership proof to spend them.
> They don't have to have stored the data themselves, but they must
> get it from somewhere-- including archive nodes that serve this
> purpose rather than having every full node carry all that data forever.
>=20
> Please be conservative with the send button. The list loses its
> utility if every moderately complex idea is hit with reflexive
> opposition by people who don't understand it.
>=20
> Peter Todd has proposed something fairly similar with "STXO
> commitments". The primary argument against this kind of approach that
That's incorrect terminology - what I proposed are "TXO commitments". I
proposed that a MMR of all prior transaction outputs's, spent and
unspent, be committed too in blocks along with a spentness flag, not
just spent transaction outputs.
That's why I often use the term (U)TXO commitments to refer to both
classes of proposals.
> I'm aware of is that the membership proofs get pretty big, and if too
> aggressive this trades bandwidth for storage, and storage is usually
> the cheaper resource. Though at least the membership proofs could be
> omitted when transmitting to a node which has signaled that it has
> kept the historical data anyways.
What I proprosed is that a consensus-critical maximum UTXO age be part
of the protocol; UTXO's younger than that age are expected to be cached.
For UTXO's older than that age, they can be dropped from the cache,
however to spend them you are required to provide the proof, and that
proof counts as blockchain space to account for the fact that they do
need to be broadcast on the network.
The proofs are relatively large, but not so much larger than a CTxIn as
to make paying for that data infeasible.
--=20
'peter'[:-1]@petertodd.org
00000000000000000188b6321da7feae60d74c7b0becbdab3b1a0bd57f10947d
--TakKZr9L6Hm6aLOc
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature
-----BEGIN PGP SIGNATURE-----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==
=J/FO
-----END PGP SIGNATURE-----
--TakKZr9L6Hm6aLOc--
|
