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
|
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 32D50CAD
for <bitcoin-dev@lists.linuxfoundation.org>;
Fri, 23 Sep 2016 18:57:59 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-ua0-f182.google.com (mail-ua0-f182.google.com
[209.85.217.182])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 96B56184
for <bitcoin-dev@lists.linuxfoundation.org>;
Fri, 23 Sep 2016 18:57:58 +0000 (UTC)
Received: by mail-ua0-f182.google.com with SMTP id 15so54744839uai.3
for <bitcoin-dev@lists.linuxfoundation.org>;
Fri, 23 Sep 2016 11:57:58 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
h=mime-version:sender:in-reply-to:references:from:date:message-id
:subject:to; bh=DzcZHMJ4JitBnuz2ieuCx8LG8BfkWBjKO9zcfItnSa4=;
b=HTWVcx8VotnFjrKqjXMsUe37DkWD67X9Jdcg3iXHnsTuRukBI/l1XSkYf7YeNTHAtC
al8Ytwm6aaHShwrs4Y2BaZDLLjgUrupsJuOqWZYg0R80sMt1lrpg4gQmMtUueNESKYwi
EMRaEOoPUULuL33c3rDxegFcXPklFoQkUYTlVYF76FSyv0DzUVccXWdF0ylkLESORc2L
7zRoUEwIC9s+3/+H2kFaKJjSImz2o6OTYtzWPctkrqphwkB1mLJWLDMH150PgCfuc5hZ
X0QDVgvRVZr59YpGLzBtwlsyQi3fJPQmgZIpaxlASO/4myTgE49qPJDkhFUFbJKIdSyL
53dA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20130820;
h=x-gm-message-state:mime-version:sender:in-reply-to:references:from
:date:message-id:subject:to;
bh=DzcZHMJ4JitBnuz2ieuCx8LG8BfkWBjKO9zcfItnSa4=;
b=Q3KY0aEqaLS07w367cGaD3mR0k7PPfOqtbNjCc+0rSfshgUZtwua9XAwsWZbD6z0qj
E4dAnEXzneO0NIkje1k8Kr9g64RTyC+N3jY0QotYdSH+SLi66VkitOs0DdXqx+Mj85xI
QK68FmBnWAzliNxhD4+EdkXmFEhbuVjHPnD7TNaeyEKUjulZpeE6hi1d/p+A5ySJnYXL
AmOlK6ahDrLEGhoFuze9hAwCnCZQAIsmkxZszUdggaHi5dvc1y/f+acbZ8Mw1hThOtRw
2Is6uivEZy0pt5/deMiHMyjpolle/81Si3vpN15ynhlKe81XC/RHEZb1ZDMUKvSK0V5B
CHcA==
X-Gm-Message-State: AA6/9Rnpi+fBZolbFmmsfClkR72duqtCajCOvtEXJjv+ai7x0c/dGV2bHSFvKIt+0swXoCU9nkyLwQoB/QBklw==
X-Received: by 10.176.5.129 with SMTP id e1mr5721662uae.114.1474657077634;
Fri, 23 Sep 2016 11:57:57 -0700 (PDT)
MIME-Version: 1.0
Sender: gmaxwell@gmail.com
Received: by 10.103.33.145 with HTTP; Fri, 23 Sep 2016 11:57:57 -0700 (PDT)
In-Reply-To: <CAAS2fgQGC695mkyze+mVTZZoQN1mh+1y32u-D6Yv1R7nXWPDcg@mail.gmail.com>
References: <201609230957.03138.luke@dashjr.org>
<CAMZUoKnY7s1b75Z_0QCb2hh-Q_hCE4-9dZ9tY58HaUQy6=aCbw@mail.gmail.com>
<CAAS2fgQGC695mkyze+mVTZZoQN1mh+1y32u-D6Yv1R7nXWPDcg@mail.gmail.com>
From: Gregory Maxwell <greg@xiph.org>
Date: Fri, 23 Sep 2016 18:57:57 +0000
X-Google-Sender-Auth: 7CqjqylK7fp0RywCps-G3Pdn_G4
Message-ID: <CAAS2fgTJ9iPoE6fvMBhFB8ruwy-6aTo4Ka5agK+LHjSqGa2-rw@mail.gmail.com>
To: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: text/plain; charset=UTF-8
X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,
DKIM_VALID, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,
RCVD_IN_SORBS_SPAM autolearn=no version=3.3.1
X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on
smtp1.linux-foundation.org
Subject: Re: [bitcoin-dev] BIP draft: OP_CHECKBLOCKATHEIGHT
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: Fri, 23 Sep 2016 18:57:59 -0000
On Fri, Sep 23, 2016 at 1:43 PM, Russell O'Connor via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:
> I believe Bitcoin currently enjoys the property that during an "innocent"
> re-org, i.e. a reorg in which no affected transactions are being double
> spent, all affected transactions can always eventually get replayed, so long
> as the re-org depth is less than 100.
> My concern with this proposed operation is that it would destroy this
> property.
The reorg safety impact of this proposal could be eliminated and the
mempool handling complexity greatly reduced if the transaction was
required to be locktimed at least 100 blocks after the block its
referencing.
This would also resolve a rather severe DOS weakness that the spec has
with the suggestion that nodes would relay this rule without
validating it. With the depth restriction nodes could relay one (or a
couple) blocks early without creating a situation where someone can
consume relay resources with near zero odds of paying a fee for them.
Irritatingly, applications of this rule would really want to be
applied at signing time (like locktime is), not as part of a
scriptpubkey. With it part of a scriptpubkey two moves are required. I
think solving this is important.
FWIW, this scheme more has been proposed before for another reason--
effectively allowing users to 'vote against' long reorgs by making
sure their transactions can't be included in them. Though for that
application it was only needed to use 32 bits of the block hash.
|
