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
|
Return-Path: <bram@bittorrent.com>
Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org
[172.17.192.35])
by mail.linuxfoundation.org (Postfix) with ESMTPS id CD85998C
for <bitcoin-dev@lists.linuxfoundation.org>;
Thu, 6 Apr 2017 02:39:09 +0000 (UTC)
X-Greylist: whitelisted by SQLgrey-1.7.6
Received: from mail-it0-f48.google.com (mail-it0-f48.google.com
[209.85.214.48])
by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 3FB6AF0
for <bitcoin-dev@lists.linuxfoundation.org>;
Thu, 6 Apr 2017 02:39:09 +0000 (UTC)
Received: by mail-it0-f48.google.com with SMTP id e75so93866919itd.1
for <bitcoin-dev@lists.linuxfoundation.org>;
Wed, 05 Apr 2017 19:39:09 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=bittorrent-com.20150623.gappssmtp.com; s=20150623;
h=mime-version:in-reply-to:references:from:date:message-id:subject:to
:cc; bh=a6Z94EjCqEXNewByOz36bfcD9h6Bh9J9WH4d6SQp6Mc=;
b=jchjG1C+ekMLnMjHDxoMw1AsFV3+gULXU7ZT4XlwhcoNSpbUiNl2oNZVX8zp/b/ZYs
/t9C236sEOks91j/BUGiHYaPwFbw+ia77jCTxMAoYiW59qNAHrXAs+BnF1s81ezNhetG
3AqHOAPfLdXUdQWRbXeAOYnXVWyPIVpczQyT5YloNlPi4IJObMOkrKTwLO1FLijjNk+4
N6MPm6c6YCvfSQOtG3llNLhw80ccOg8eCsmONWDB892aBSetgzcHUAXE1lVLXm8J0JnI
c2FOr+h13tFcx9CXt5/1nHmZp3juIe9ZGghCsRkpAWYko6/F8zLMpNiDO10InRLoh0a+
gZNQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:in-reply-to:references:from:date
:message-id:subject:to:cc;
bh=a6Z94EjCqEXNewByOz36bfcD9h6Bh9J9WH4d6SQp6Mc=;
b=UaSBZa8DFiTjS1xiXQOGiOgs0lhH40FPmJZ1/PVUzszGldGLGkbHv1r8/Kdw7jBCvo
DdiCEYt8RIDtxPf8UjSfksvLljHaZv0ulZZcIKwQ5KR5Xs0qMiY0nwcVbAb0eMD1b41u
GeF+8tnKt34oEhvFQI8S2e+ZUaZg+jGeJe544EpFyCxIZhqcjj3bBCm+InZGufFAG22v
qVmuD+qu3u5EVDPAzavI3vcRaTFrQkMlY5cak18FiLUyI4v+3yND9RjBOGxCmDijGg1F
J92pMG76qof05UauJWz4B+2UADCi2oCi1NhyLuVT2S1T2GXRsGT5GdX+qI2pU9kXwLFZ
JhiA==
X-Gm-Message-State: AFeK/H0RSORDXgFpQbgVd88VZV8Sqf07kwmWIy0sjHkHe9LYDz2Y00ym
XrcGhZizzfzqyX6I8v2HJgut0QUXDgA1
X-Received: by 10.36.107.214 with SMTP id v205mr24323755itc.65.1491446348638;
Wed, 05 Apr 2017 19:39:08 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.36.184.70 with HTTP; Wed, 5 Apr 2017 19:39:08 -0700 (PDT)
In-Reply-To: <20170406023123.GA1071@savin.petertodd.org>
References: <CAAS2fgR84898xD0nyq7ykJnB7qkdoCJYnFg6z5WZEUu0+-=mMA@mail.gmail.com>
<20170406023123.GA1071@savin.petertodd.org>
From: Bram Cohen <bram@bittorrent.com>
Date: Wed, 5 Apr 2017 19:39:08 -0700
Message-ID: <CA+KqGkqSxeAUZFVFqM_QkEWcGFHgZXwGuOE==7HpXp1+D_Tj3Q@mail.gmail.com>
To: Peter Todd <pete@petertodd.org>,
Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Content-Type: multipart/alternative; boundary=001a114ac8f6d03947054c7669bc
X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,
DKIM_VALID, HTML_MESSAGE, 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 proposal: Inhibiting a covert attack on the
Bitcoin POW function
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: Thu, 06 Apr 2017 02:39:09 -0000
--001a114ac8f6d03947054c7669bc
Content-Type: text/plain; charset=UTF-8
On Wed, Apr 5, 2017 at 7:31 PM, Peter Todd via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:
>
> While I'm in favour of blocking covert usage of ASICBOOST, there's every
> reason
> to block non-covert usage of it as well. In a low margin business like
> mining,
> the advatange it gives is enormous - quite possibly 10x your profit margin
> -
> and given that barrier free access to being able to purchase ASICs is
> already
> an archilles heal for Bitcoin there is every reason to eliminate this legal
> vulnerability. Additionally, it's a technical vulnerability as well: we
> want
> getting into the ASIC manufacturing and design business to have as low
> barriers
> to entry as is feasible, and the ASICBOOST exploit significantly increases
> the
> minimum capital requirements to do so.
>
Asicboost also has the problem that it isn't treating the hashing as a
black box, and thus has impacts on what gets mined. In particular it
creates an incentive to make blocks smaller. That's a very unwanted effect,
and anything like it should be engineered out on principle.
--001a114ac8f6d03947054c7669bc
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
<div dir=3D"ltr"><div class=3D"gmail_extra"><div class=3D"gmail_quote">On W=
ed, Apr 5, 2017 at 7:31 PM, Peter Todd via bitcoin-dev <span dir=3D"ltr">&l=
t;<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank=
">bitcoin-dev@lists.linuxfoundation.org</a>></span> wrote:<br><blockquot=
e class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc sol=
id;padding-left:1ex"><span class=3D""><br>
</span>While I'm in favour of blocking covert usage of ASICBOOST, there=
's every reason<br>
to block non-covert usage of it as well. In a low margin business like mini=
ng,<br>
the advatange it gives is enormous - quite possibly 10x your profit margin =
-<br>
and given that barrier free access to being able to purchase ASICs is alrea=
dy<br>
an archilles heal for Bitcoin there is every reason to eliminate this legal=
<br>
vulnerability. Additionally, it's a technical vulnerability as well: we=
want<br>
getting into the ASIC manufacturing and design business to have as low barr=
iers<br>
to entry as is feasible, and the ASICBOOST exploit significantly increases =
the<br>
minimum capital requirements to do so.<br></blockquote><div><br></div><div>=
Asicboost also has the problem that it isn't treating the hashing as a =
black box, and thus has impacts on what gets mined. In particular it create=
s an incentive to make blocks smaller. That's a very unwanted effect, a=
nd anything like it should be engineered out on principle.</div></div></div=
></div>
--001a114ac8f6d03947054c7669bc--
|
