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
|
Return-Path: <gmaxwell@gmail.com>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id 093B092B
for <bitcoin-dev@lists.linuxfoundation.org>;
Tue, 16 May 2017 00:00:00 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-vk0-f49.google.com (mail-vk0-f49.google.com
[209.85.213.49])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5E129E9
for <bitcoin-dev@lists.linuxfoundation.org>;
Mon, 15 May 2017 23:59:59 +0000 (UTC)
Received: by mail-vk0-f49.google.com with SMTP id y190so57421506vkc.1
for <bitcoin-dev@lists.linuxfoundation.org>;
Mon, 15 May 2017 16:59:59 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
h=mime-version:sender:in-reply-to:references:from:date:message-id
:subject:to:cc;
bh=kHw66TQ8xUaKbTbpBS6OR92vGgMpKYFKLMG/8C3CMAg=;
b=QT85x3xQDJFaLKq7T/j8MOO0Yd1dZrjBRPjx/VTT19MBWQpGwgyBXCGsursyXlXLO4
J+SEUXQRdUyvEpT3c/Z7NMzb6WARhohgOEDKFWuF+79t0QER5dKWsTpGZ+Ib93k4/pMq
Y7TzQ4kqdAiXq06iMvDM6v9tn1h+jAzfhOHeVx7D33JeVl6jSKSN4nMeDucEb7gFQU6n
Fx7kzwaPZK8jBLeQfQaFM2Hmwr5iLBzbtJvcNgtyh/AYc69eplSTUskD3bsedAbJeVSs
N1QJgLiAUJRBLPdpemU/L4mHIDSvyWLjabP5iJ5hlcefujmSWCtQH3Ql6FnxTCTyXu0Y
m+4g==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:sender:in-reply-to:references:from
:date:message-id:subject:to:cc;
bh=kHw66TQ8xUaKbTbpBS6OR92vGgMpKYFKLMG/8C3CMAg=;
b=Kk3BSA8eqpWvPB5AVDPwJoab3aR3tUFG5NkoYwSDAjsOsKhtRgKIyNhmZVxZZrhpMq
BJHEvxHPNUIYWX6KSJehYfkVldOEvLGM31RPBHE/ecRSbozQlCgPIFFdOgUXXYQfdp8+
QAofuGHQtMfT+f7v7qgu8e/eUCVWeqozylZFgDZOk9p6nh9t7Lzse+Mn9ex9d83N+dUL
ojm1xtrlIpz/lT504Tp6nvhiS1Nx144dKCXL6rlQYYP2fs4D/GMAAg7AqJPcJ/qxtD6Q
1U4/5lprxlLWeGM+5e2Zx0qslaHzg8loMzTYfmBExu2/IZ00nxFs3csoeuMy8BYNKvZe
XdvQ==
X-Gm-Message-State: AODbwcDVBXEsnRQ8ZCTKify451Ebsssq3oBZ6F9yQNklyOhCcsF85udz
7VFO4QmQrP9JU/5mMhQwWpk9JRwvtQ==
X-Received: by 10.31.137.145 with SMTP id l139mr4269911vkd.39.1494892798543;
Mon, 15 May 2017 16:59:58 -0700 (PDT)
MIME-Version: 1.0
Sender: gmaxwell@gmail.com
Received: by 10.103.20.66 with HTTP; Mon, 15 May 2017 16:59:58 -0700 (PDT)
In-Reply-To: <CT3GNfkLsQJyM0EmWXc3HBmnW1h2iptP0SohZnXZfZPffoVmcofD8fs_E3kV5PuFL0pQSQwwk_FyR-8-wdANf15NE8UElNWqcEcc5Ql3n8M=@protonmail.com>
References: <CAPg+sBgruEiXya6oFy6VpmR1KPDebjeGDtZZU+facZx5=L_a5w@mail.gmail.com>
<CT3GNfkLsQJyM0EmWXc3HBmnW1h2iptP0SohZnXZfZPffoVmcofD8fs_E3kV5PuFL0pQSQwwk_FyR-8-wdANf15NE8UElNWqcEcc5Ql3n8M=@protonmail.com>
From: Gregory Maxwell <greg@xiph.org>
Date: Mon, 15 May 2017 23:59:58 +0000
X-Google-Sender-Auth: rsiJSVyIlVPUlULgTuwLXj8MpVk
Message-ID: <CAAS2fgTif+Y6VzFG+w7W+CY1+D_roCqGyy392qB2KcDPGpVeiw@mail.gmail.com>
To: ZmnSCPxj <ZmnSCPxj@protonmail.com>
Content-Type: text/plain; charset="UTF-8"
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,
DKIM_VALID, FREEMAIL_FROM,
RCVD_IN_DNSWL_NONE 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] Rolling UTXO set hashes
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: Tue, 16 May 2017 00:00:00 -0000
On Mon, May 15, 2017 at 11:04 PM, ZmnSCPxj via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:
> transactions is in the header, which would let lite nodes download a UTXO
> set from any full node and verify it by verifying only block headers
> starting from genesis.
Ya, lite nodes with UTXO sets are one of the the oldest observed
advantages of a commitment to the UTXO data:
https://bitcointalk.org/index.php?topic=21995.0
But it requires a commitment. And for most of the arguments for those
you really want compact membership proofs. The recent rise in
interest in full block lite clients (for privacy reasons), perhaps
complements the membership proofless usage.
Pieter describes some uses for doing something like this without a
commitment. In my view, it's more interesting to first gain
experience with an operation without committing to it (which is a
consensus change and requires more care and consideration, which are
easier if people have implementation experience).
> rather than merkle tree root of transactions is in the header,
For audibility and engineering reasons it would need to be be in
addition to rather than rather than, because the proof of work needs
to commit to the witness data (in that kind of flip, the transactions
themselves become witnesses for UTXO deltas) or you get trivial DOS
attacks where people provide malleated blocks that have invalid
witnesses.
|
